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PrinciplesofChemicalNomenclatureAGUIDETOIUPACRECOMMENDATIONSPrinciplesofChemicalNomenclatureAGUIDETOIUPACRECOMMENDATIONSG.
J.
LEIGHOBETheSchoolofChemistry,PhysicsandEnvironmentalScience,UniversityofSussex,Brighton,UKH.
A.
FAVREUniversitédeMontréalMontréal,CanadaW.
V.
METANOMSKIChemicalAbstractsServiceColumbus,Ohio,USAEditedbyG.
J.
LeighbBlackwellScience1998byBlackweilScienceLtdEditorialOffices:OsneyMead,Oxford0X20EL25JohnStreet,LondonWC1N2BL23AinsliePlace,EdinburghEH36AJ350MainStreet,MaidenMA02148-5018,USA54UniversityStreet,CarltonVictoria3053,Australia10,RueCasmirDelavigne75006Paris,FranceOtherEditorialOffices:BlackwellWissenschafts-VerlagGmbHKurfUrstendamm5710707Berlin,GermanyBlackwellScienceKKMGKodenmachoBuilding7—10KodenmachoNihombashiChuo-ku,Tokyo104,JapanAllrightsreserved.
Nopartofthispublicationmaybereproduced,storedinaretrievalsystem,ortransmitted,inanyformorbyanymeans,electronic,mechanical,photocopying,recordingorotherwise,exceptaspermittedbytheUKCopyright,DesignsandPatentsAct1988,withoutthepriorpermissionofthecopyrightowner.
Firstpublished1998SetbySemanticGraphics,SingaporePrintedandboundinGreatBritainbyMPGBooksLtd,Bodmin,CornwallTheBlackwellSciencelogoisatrademarkofBlackwellScienceLtd,registeredattheUnitedKingdomTradeMarksRegistryDISTRIBUTORSMarstonBookServicesLtdP0Box269AbingdonOxon0X144YN(Orders:Tel:01235465500Fax:01235465555)USABlackwellScience,Inc.
CommercePlace350MainStreetMalden,MA02148-5018(Orders:Tel:80075961027813888250Fax:7813888255)CanadaCoppClarkProfessional200AdelaideStWest,3rdFloorToronto,OntarioM5H1W7(Orders:Tel:416597-1616800815-9417Fax:416597-1617)AustraliaBlackwellSciencePtyLtd54UniversityStreetCarlton,Victoria3053(Orders:Tel:393470300Fax:393475001)AcataloguerecordforthistitleisavailablefromtheBritishLibraryISBN0-86542-685-6LibraryofCongressCataloging-in-publicationDataLeigh,G.
J.
Principlesofchemicalnomenclature:aguidetoIUPACrecommendations/G.
J.
Leigh,H.
A.
Favre,W.
V.
Metanomski.
p.
cm.
Includesbibliographicalreferencesandindex.
ISBN0-86542-685-61.
Chemistry—Nomenclature.
I.
Favre,H.
A.
II.
Metanomski,W.
V.
III.
InternationalUnionofPureandAppliedChemistry.
IV.
Title.
QD7.
L441997540'.
14—dc2i97-28587CIPContentsPreface,vii1INTRODUCTION,12DEFINITIONS,33FORMULAE,93.
1Introduction,93.
2Empiricalformulae,93.
3Molecularformulae,93.
4Structuralformulae,103.
5Sequenceofcitationofsymbols,113.
6Formulaeofgroups,133.
7Three-dimensionalstructuresandprojections,163.
8Isomersandstereoisomers,214NAMINGOFSUBSTANCES,264.
1Typesofnomenclature,264.
2Binary-typenomenclature,274.
3Morecomplexnomenclaturesystems,494.
4Coordinationnomenclature,anadditivenomenclature,514.
5Substitutivenomenclature,704.
6Functionalclassnomenclature,965ASPECTSOFTHENOMENCLATUREOFORGANOMETALLICCOMPOUNDS,985.
1General,985.
2DerivativesofMainGroupelements,985.
3Organometallicderivativesoftransitionelements,1026MACROMOLECULAR(POLYMER)NOMENCLATURE,1036.
1Definitions,1036.
2Generalconsiderations,1046.
3Source-basednomenclature,1056.
4Structure-basednomenclature,1056.
5Tradenamesandabbreviations,113VCONTENTS7BIOCHEMICALNOMENCLATURE,1147.
1Introduction,1147.
2Carbohydratenomenclature,1147.
3Nomenclatureandsymbolismforaminoacidsandpeptides,1187.
4Lipidnomenclature,1217.
5Steroidnomenclature,1228NOMENCLATUREINTHEMAKING,124Index,127viPrefaceThisbookaroseoutoftheconvictionsthatIUPACnomenclatureneedstobemadeasaccessibleaspossibletoteachersandstudentsalike,andthatthereisanabsenceofrelativelycompleteaccountsoftheIUPAC'colour'bookssuitedtoschoolandundergraduateaudiences.
ThisisnottodecryinanywaytheeffortsoforganisationssuchastheAssociationforScienceEducation(ASE)intheUK,butwhatwewishedtoproducewasaversionofIUPACrulesthatwouldberelativelycompleteandallowthebeginnertoexploreandlearnaboutnomenclatureasmuchoraslittleasdesired.
Initially,itwasintendedtoproduceabookthatwouldcoverallIUPACcolourbooksandencompassmuchmorethanwhatisconventionallyregardedasnomen-clature,e.
g.
dealingalsowithunits,kineticsandanalysis.
AcommitteeconsistingofC.
J.
H.
Schutte(SouthAfrica),J.
R.
Bradley(SouthAfrica),T.
Cvita(Croatia),S.
Gb(Poland),H.
A.
Favre(Canada)andG.
J.
Leigh(UK)wassetuptoproduceadraftofthisbook.
Later,theywerejoinedbyW.
V.
Metanomski(USA).
Whenthefirstdrafthadbeenprepared,itwasevidentthattheconventionalnomenclaturesectionwassolargethatitunbalancedthewholeproduction.
Finally,itwasdecidedtopreparetwotexts,onefollowingtheoriginalproposal,butwithamuchreducednomenclaturecontentinordertorestorethebalance,andasecond,thisvolume,thatwouldattempttosurveythecurrentIUPACnomencla-turerecommendationsinorganic,inorganicandmacromolecularchemistryandalsoincludesomebasicbiochemicalnomenclature.
ThiswasundertakenbyFavre,LeighandMetanomski,withthefinaleditingbeingundertakenbyLeigh.
Itishopedthatthisvolumewillmorethancoverallthenomenclaturerequire-mentsofstudentsatpre-Universityandearlyundergraduatelevelsinmostcoun-tries.
ItshouldalsoenableUniversitystudentsandteacherstolearnthebasicprinciplesofnomenclaturemethodssothattheycanapplythemaccuratelyandwithconfidence.
Itwillprobablybetooadvancedforschoolstudents,butshouldbeusefulfortheirteachers.
Specialistsinnomenclaturerecognisetwodifferentcategoriesofnomenclature.
Namesthatarearbitrary(includingthenamesoftheelements,suchassodiumandhydrogen)aswellaslaboratoryshorthandnames(suchasdiphosandLithAl)aretermedtrivialnames.
Thisisnotapejorativeordismissiveterm.
Trivialnomencla-turecontrastswithsystematicnomenclature,whichisdevelopedaccordingtoasetofprescribedrules.
However,nomenclature,likeanylivinglanguage,isgrowingandchanging.
ThisisreflectedbythefactthatIUPACdoesnotprescribeasinglenameforeachandeverycompound.
Thereareseveralextantsystemsofnomenclatureandmanytrivialnamesarestillinuse.
Thismeansthatthechemistoftenhasaselectionofnamesfromwhichtochoose.
IUPACmayprefersomenamesandallowothers,andthenameselectedshouldgenerallybe,withinreason,asystematicone.
BecauseIUPACcannotlegislate,butcanonlyadvise,chemistsshouldfeelfreetobacktheirownjudgement.
Forexample,thesystematicnameforNH3isazane,butitisnotrecommendedforgeneraluseinplaceoftheusual'ammonia'.
Ontheotherhand,thereseemstobenoviiPREFACEgoodreasonwhychemistsgenerallyshouldnotadoptthemoresystematicphos-phane,ratherthanphosphine,forPH3.
Studentsmayfindthismatterofchoiceconfusingonoccasion,whichwillbeapity.
However,therearecertainlong-establishedprinciplesthatendure,andwehopetohaveencompassedtheminthisbook.
G.
J.
LeighUniversityofSussexJune1997viiiIntroductionChemicalnomenclatureisatleastasoldasthepseudoscienceofalchemy,whichwasabletorecognisealimitednumberofreproduciblematerials.
Thesewereassignednamesthatoftenconveyedsomethingofthenatureofthematerial(vitriol,oilofvitriol,butteroflead,aquafortis.
.
.
).
Aschemistrybecamearealscience,andprinciplesofthemodernatomictheoryandchemicalcombinationandconstitutionweredeveloped,suchnamesnolongersufficedandthepossibilityofdevelopingsystematicnomenclatureswasrecognised.
ThenamesofGuytondeMorveau,Lavoisier,Berthollet,FourcroyandBerzeliusareamongthosenotableforearlycontributions.
Thegrowthoforganicchemistryinthenineteenthcenturywasassociatedwiththedevelopmentofmoresystematicnomenclatures,andchemistssuchasLiebig,DumasandWernerareassociatedwiththeseinnovations.
Thesystematisationoforganicchemistryinthenineteenthcenturyledtotheearlyrecognitionthatasystematicandinternationallyacceptablesystemoforganicnomenclaturewasnecessary.
In1892,theleadingorganicchemistsofthedaygatheredinGenevatoestablishjustsuchasystem.
TheGenevaConventionthattheydrewupwasonlypartlysuccessful.
However,itwastheforerunnerofthecurrentactivitiesoftheInternationalUnionofPureandAppliedChemistry(IUPAC)anditsCommissiononNomenclatureofOrganicChemistry(CNOC),whichhastheremittostudyallaspectsofthenomenclatureoforganicsubstances,torecommendthemostdesirablepractices,systematisingtrivial(i.
e.
non-systematic)methods,andtoproposedesirablepracticestomeetspecificproblems.
TheCommis-sionontheNomenclatureofInorganicChemistry(CNIC)wasestablishedratherlater,becauseofthelatersystematisationofthisbranchofthesubject,anditnowfulfilsfunctionssimilartothoseofCNOCbutininorganicchemistry.
Inareasofjointinterest,suchasorganometallicchemistry,CNICandCNOCcollaborate.
TherecommendationsoutlinedherearederivedfromthoseoftheseIUPACCommis-sions,andoftheCommissiononMacromolecularNomenclature(COMN)andoftheInternationalUnionofBiochemistryandMolecularBiology(IUBMB).
Thesystematicnamingofsubstancesandpresentationofformulaeinvolvetheconstructionofnamesandformulaefromunitsthataremanipulatedinaccordancewithdefinedproceduresinordertoprovideinformationoncompositionandstructure.
Thereareanumberofacceptedsystemsforthis,ofwhichtheprincipaloneswillbediscussedbelow.
Whateverthepatternofnomenclature,namesandformulaeareconstructedfromunitsthatfallintothefollowingclasses:Elementnames,elementnameroots,elementsymbols.
Parenthydridenames.
Numericalprefixes(placedbeforeaname,butjoinedtoitbyahyphen),infixes(insertedintoaname,usuallybetweenhyphens)andsuffixes(placedafteraname).
Locants,whichmaybelettersornumerals,andmaybeprefixes,infixesorsuffixes.
Prefixesindicatingatomsorgroups—eithersubstituentsorligands.
Suffixesintheformofasetoflettersorcharactersindicatingcharge.
Suffixesintheformofasetoflettersindicatingcharacteristicgroups.
Infixesintheformofasetoflettersorcharacters,withvarioususes.
CHAPTER1Additiveprefixes:asetoflettersorcharactersindicatingtheformaladditionofparticularatomsorgroupstoaparentmolecule.
Subtractivesuffixesand/orprefixes:asetoflettersorcharactersindicatingtheabsenceofparticularatomsorgroupsfromaparentmolecule.
Descriptors(structural,geometric,stereochemical,etc.
).
Punctuationmarks.
Theusesofallthesewillbeexemplifiedinthediscussionbelow.
ThematerialdiscussedhereisbasedprimarilyonAGuidetoIUPACNomencla-tureofOrganicChemistry,Recommendations1993,issuedbyCNOC,ontheNomenclatureofInorganicChemistry,Recommendations1990(theRedBook),issuedbyCNIC,ontheCompendiumofMacromolecularChemistry(thePurpleBook),issuedin1991byCOMN,andonBiochemicalNomenclatureandRelatedDocuments,2ndEdition1992(theWhiteBook),issuedbyIUBMB.
Inmanycases,itwillbenotedthatmorethanonenameissuggestedforaparticularcompound.
Oftenapreferrednamewillbedesignated,butasthereareseveralsystematicorsemi-systematicnomenclaturesystemsitmaynotbepossible,orevenadvisable,torecommendauniquename.
Inaddition,manynon-systematic(trivial)namesarestillingeneraluse.
Althoughitishopedthatthesewillgraduallydisappearfromtheliterature,manyarestillretainedforpresentuse,althoughofteninrestrictedcircumstances.
Theserestrictionsaredescribedinthetext.
Theuserofnomenclatureshouldadoptthenamemostsuitableforthepurposeinhand.
22DefinitionsAnelement(oranelementarysubstance)ismatter,theatomsofwhicharealikeinhavingthesamepositivechargeonthenucleus(oratomicnumber).
Incertainlanguages,acleardistinctionismadebetweentheterms'element'and'elementarysubstance'.
InEnglish,itisnotcustomarytomakesuchnicedistinc-tions,andtheword'atom'issometimesalsousedinterchangeablywithelementorelementarysubstance.
Particularcareshouldbeexercisedintheuseandcomprehen-sionoftheseterms.
Anatomisthesmallestunitquantityofanelementthatiscapableofexistence,whetheraloneorinchemicalcombinationwithotheratomsofthesameorotherelements.
Theelementsaregivennames,ofwhichsomehaveoriginsdeepinthepastandothersarerelativelymodern.
Thenamesaretrivial.
Thesymbolsconsistofone,twoorthreeromanletters,oftenbutnotalwaysrelatedtothenameinEnglish.
Examples1.
HydrogenH2.
ArgonAr3.
PotassiumK4.
SodiumNa5.
ChlorineCl6.
UnunquadiumUuqForalongerlist,seeTable2.
1.
Fortheheavierelementsasyetunnamedorunsynthesised,thethree-lettersymbols,suchasUuq,andtheirassociatednamesareprovisional.
Theyareprovidedfortemporaryuseuntilsuchtimeasaconsensusisreachedinthechemicalcommunitythattheseelementshaveindeedbeensynthe-sised,andatrivialnameandsymbolhavebeenassignedaftertheprescribedIUPACprocedureshavetakenplace.
Whentheelementsaresuitablyarrangedinorderoftheiratomicnumbers,aPeriodicTableisgenerated.
Therearemanyvariants,andanIUPACversionisshowninTable2.
2.
Anatomicsymbolcanhaveuptofourmodifierstoconveyfurtherinformation.
ThisisshownforahypotheticalatomicsymbolX:DAxCBModifierAindicatesachargenumber,whichmaybepositiveornegative(whenelementXismoreproperlycalledanion).
IntheabsenceofmodifierA,thechargeisassumedtobezero.
Alternativelyoradditionally,itcanindicatethenumberofunpairedelectrons,inwhichcasethemodifierisacombinationofanarabicnumeralandadot.
Thenumber'one'isnotrepresented.
3CHAPTER2Table2.
1Names,symbolsandatomicnumbersoftheatoms(elements).
NameSymbolAtomicnumberNameSymbolAtomicnumberActiniumAc89Mercury6Hg80AluminiumAl13MolybdenumMo42AmericiumAm95NeodymiumNd60Antimony1Sb51NeonNe10ArgonAr18NeptuniumNp93ArsenicAs33NickelNi28AstatineAt85NiobiumNb41BariumBa56Nitrogen7N7BerkeliumBk97NobeliumNo102BerylliumBe4OsmiumOs76BismuthBi83Oxygen08BohriumBh107PalladiumPd46BoronB5PhosphorusP15BromineBr35PlatinumPt78CadmiumCd48PlutoniumPu94CaesiumCs55PoloniumPo84CalciumCa20Potassium8K19CaliforniumCf98PraseodymiumPr59CarbonC6PromethiumPm61CeriumCe58ProtactiniumPa91ChlorineCl17RadiumRa88ChromiumCr24RadonRn86CobaltCo27RheniumRe75Copper2Cu29RhodiumRh45CuriumCm96RubidiumRb37DubniumDb105RutheniumRu44DysprosiumDy66RutherfordiumRf104EinsteiniumEs99SamariumSm62ErbiumEr68ScandiumSc21EuropiumEu63SeaborgiumSg106FermiumFm100SeleniumSe34FluorineF9SiliconSi14FranciumFr87Silver9Ag47GadoliniumGd64Sodium'°Na11GalliumGa31StrontiumSr38GermaniumGe32Sulfur"S16Gold3Au79TantalumTa73HafniumHf72TechnetiumTc43HassiumHs108TelluriumTe52HeliumHe2TerbiumTb65HolmiumHo67ThalliumTl81Hydrogen4H1ThoriumTh90IndiumIn49ThuliumTm69IodineI53Tin'2Sn50IridiumIr77TitaniumTi22Iron5Fe26Tungsten'3W74KryptonKr36UnunbiiumUub112LanthanumLa57UnunhexiumUuh116LawrenciumLr103UnunniliumUun110LeadPb82UnunoctiumUuo118LithiumLi3UnunpentiumUup115LutetiumLu71UnunquadiumUuq114MagnesiumMg12UnunseptiumUus117ManganeseMn25UnuntriiumUut113MeitneriumMt109UnununiumUnu111MendeleviumMd101UraniumU92Continued.
4Table2.
1(Continued.
)DEFINITIONSNameSymbolAtomicnumberNameSymbolAtomicnumberVanadiumV23YttriumY39XenonXe54ZincZn30YtterbiumYb70ZirconiumZr401SymbolderivedfromtheLatinnamestibium.
2SymbolderivedfromtheLatinnamecuprum.
SymbolderivedfromtheLatinnameaurum.
"Thehydrogenisotopes2Hand3Harenameddeuteriumandtritium,respectively,forwhichthesymbolsDandTmaybeused.
SymbolderivedfromtheLatinnameferrum.
6SymbolderivedfromtheLatinnamehydrargyrum.
Thenameazoteisusedtodevelopnamesforsomenitrogencompounds.
8SymbolderivedfromtheLatinnamekalium.
SymbolderivedfromtheLatinnameargentum.
derivedfromtheLatinnamenatrium.
TheGreeknametheionprovidestheroot'thi'usedinnamesofsulfurcompounds.
12SymbolderivedfromtheLatinnamestannum.
13SymbolderivedfromtheGermanicnamewolfram.
Examples7.
Na10.
C18.
Ca211.
02_9.
N312.
N2ModifierBindicatesthenumberofatomsboundtogetherinasinglechemicalentityorspecies.
IfBis1,itisnotrepresented.
Inanempiricalformula(seebelow)itcanbeusedtoindicaterelativeproportions.
Examples13.
P414.
Cl215.
816.
C60ModifierCisusedtodenotetheatomicnumber,butthisspaceisgenerallyleftemptybecausetheatomicsymbolnecessarilyimpliestheatomicnumber.
ModifierDisusedtoshowthemassnumberoftheatombeingconsidered,thisbeingthetotalnumberofneutronsandprotonsconsideredtobepresentinthenucleus.
Thenumberofprotonsdefinestheelement,butthenumberofneutronsinatomsofagivenelementmayvary.
Anyatomicspeciesdefinedbyspecificvaluesofatomicnumberandmassnumberistermedanuclide.
Atomsofthesameelementbutwithdifferentatomicmassesaretermedisotopes,andthemassnumbercanbeusedtodesignatespecificisotopes.
Examples17.
31P18.
1H,2H(orD),3H(orT)19.
12C5Table2.
2IUPACPeriodicTableoftheElements.
r711ii55Cs56Ba57—71La-Lu72Hf73Ta74W75Re76Os77Ir78Pt79Au80Hg81Ti82Pb83Bi84Po85At86Rn687Fr88Ra89—103Ac—Lr104Rf105Db106Sg107Bh108Hs109Mt110Uun111Uuu112Uub113Uut114Uuq115Uup116Uuh117Uus118Uuo7575859606162636465666768697071LaCePrNdPmSmEuGdTbDyHoErTmYbLu678990919293949596979899100101102103AcThPaUNpPuAmCmBkCfEsFmMdNoLrDEFINITIONSNotethatofalltheisotopesofalltheelements,onlythoseofhydrogen,2Hand3H,alsohavespecificatomicsymbols,DandT,withassociatednamesdeuteriumandtritium.
Elementsfallintovariousclasses,aslaidoutinthePeriodicTable(Table2.
2).
AmongthegenerallyrecognisedclassesaretheMainGroupelements(Groups1,2,13,14,15,16,17and18),thetwoelementsoflowestatomicnumberineachgroupbeingdesignatedtypicalelements.
TheelementsofGroups3—11aretransitionelements.
Thefirstelement,hydrogen,isanomalousandformsaclassofitsown.
Othermoretrivialdesignations(alkalimetals,halogens,etc.
)arerecognised,butthesenamesarenotoftenusedinnomenclature.
Formoreinformation,consultanappropriatetextbook.
Onlyafewelementsformamonoatomicelementarysubstance.
Themajorityformpolyatomicmaterials,rangingfromdiatomicsubstances,suchasH2,N2and02,throughpolyatomicspecies,suchasP4andS8,toinfinitepolymers,suchasthemetals.
Thesepolyatomicspecies,wherethedegreeofaggregationcanbepreciselydefined,aremorecorrectlytermedmolecules.
However,theuseoftheterm'element'isnotrestrictedtotheconsiderationofelementarysubstances.
Compoundsarecomposedofatomsofthesameorofmorethanonekindofelementinsomeformofchemicalcombination.
Thuswaterisacompoundoftheelementshydrogenandoxygen.
Themoleculeofwateriscomposedofthreeatoms,twoofwhichareoftheelementhydrogenandoneoftheelementoxygen.
Itshouldbenotedhere,again,thattheterm'element'isonethatissometimesconsideredtobeanabstraction.
Itimpliestheessentialnatureofanatom,whichisretainedhowevertheatommaybecombined,orinwhateverformitexists.
Anelementarysubstanceisaphysicalformofthatelement,asitmaybepreparedandstudied.
Moleculescanalsobecharged.
Thisisnotcommoninelementarysubstances,butwheresomemoleculesoratomsarepositivelycharged(theseasaclassarecalled'cations')theymustbeaccompaniedbynegativemoleculesoratoms(anions)tomaintainelectroneutrality.
Manyelementscangiverisetomorethanoneelementarysubstance.
Thesemaybesubstancescontainingassemblagesofthesamemono-orpoly-atomicunitbutarrangeddifferentlyinthesolidstate(aswithtin),ortheymaybeassemblagesofdifferentpolyatomicunits(aswithcarbon,whichformsdiamond,graphiteandthefullerenes,andwithsulfurandoxygen).
Thesedifferentformsoftheelementarereferredtoasallotropes.
Theircommonnomenclatureisessentiallytrivial,butattemptshavebeenmadetodevelopsystematicnomenclatures,especiallyforcrystallinematerials.
Theseattemptsarenotwhollysatisfactory.
Throughoutthisdiscussion,wehavebeenconsideringpuresubstances,i.
e.
substancescomposedofasinglematerial,whetherelementorcompound.
Acom-poundmaybemolecularorionic,orboth.
Acompoundisasinglechemicalsubstance.
Toanticipateslightly,sodiumchlorideisanioniccompoundthatcontainstwoatomicspecies,NaandCl-.
IfasampleofsodiumchlorideisformallymanipulatedtoremovesomeCl-ionsandreplacethembyBrionsinequivalentnumber,theresultantmaterialisamixture.
ThesameistrueofasamplecontainingneutralspeciessuchasP4,8andC6H6.
Puresubstances(betheyelementaryorcompound)andmixturesareusuallysolids,liquidsorgases,andtheymayeventakesomerarerform.
Theseformsare7CHAPTER2termedstatesofmatterandarenotstrictlytheprovinceofnomenclature.
However,toindicatebyanameoraformulawhetherasubstanceisasolid,liquidorgas,theletterss,gor1areused.
Formoredetails,seetheGreenBook(Quantities,UnitsandSymbolsinPhysicalChemistry,2ndEdition,BlackwellScientificPublications,Oxford,1993).
Examples20.
H2O(l)21.
H20(g)22.
H20(s)83Formulae3.
1INTRODUCTIONThebasicmaterialsofsystematicchemicalnomenclaturearetheelementnamesandsymbols,whichare,ofthemselves,trivial,withtheexceptionofthesystematic,provisionalnamesandsymbolsfortheelementsofatomicnumbergreaterthan109.
Theseprovisionalnameswillbesupersededeventuallybytrivialnamesandsym-bols.
Inanycase,theymakelittleimpactongeneralchemicalpractice.
Thesimplestwaytorepresentchemicalsubstancesistouseformulae,whichareassemblagesofchemicalsymbols.
Formulaeareparticularlyusefulforlistingandindexingandalsowhennamesbecomeverycomplex.
Thepreciseformofaformulaselecteddependsupontheusetowhichitistobeput.
3.
2EMPIRICALFORMULAEThesimplestkindofformulaisacompositionalformulaorempiricalformula,whichliststheconstituentelementsintheatomicproportionsinwhichtheyarepresentinthecompound.
Forsuchaformulatobeusefulinlistsorindexes,anorderofcitationofsymbols(hierarchy)mustbeagreed.
Suchhierarchies,oftendesignatedsenioritiesorpriorities,arecommonlyusedinnomenclature.
Forlistsandindexes,theorderisnowgenerallyrecommendedtobethealphabeticalorderofsymbols,withoneveryimportantexception.
Becausecarbonandhydrogenarealwayspresentinorganiccompounds,Cisalwayscitedfirst,Hsecondandthentherest,inalphabeticalorder.
Innon-carbon-containingcompounds,strictalphabeticalorderisadheredto.
Notethatmolecularorionicmassescannotbecalculatedfromempiricalformu-lae.
Examples1.
C1K5.
CHClFe2.
Ca0456.
CH23.
CFeKN7.
CHO4.
NS3.
3MOLECULARFORMULAEMolecularformulaeforcompoundsconsistingofdiscretemoleculesareformulaeaccordingwiththerelativemolarmassorrelativemolecularmassormolecularweightforthestructure.
Examples1.
N4542.
S2Cl23.
C2H69CHAPTER3Polyatomicionsaretreatedsimilarly,althoughthechargemustalsobeindicated.
Theseformulaetellnothingaboutstructure.
Assoonasstructuralinformationiscombinedwiththeformula,thesesimplerulesneedtobeamplified.
Itshouldbenotedthatthediscussionsofarhasassumedthatallcompoundsarestoichiometric,i.
e.
thatalltheatomicormolecularproportionsareintegral.
Ithasbecomeincreasinglyclearthatmanycompoundsaretosomedegreenon-stoichiometric.
Theserulesfailfornon-stoichiometriccompounds,forwhichfurtherformalismsneedtobedeveloped.
Electroneutralitymust,ofcourse,bemaintainedoverallinsuchcompounds,inonewayoranother.
Forexample,inanioniccompoundwherethereisapparentlyadeficitofnegativeions,theconsequentformalexcessofcationsmaybeneutralisedbythepresenceofanappropriatenumberofcationsoftheformM1)±ratherthanoftheprevalentformM'.
Variousstratagemshavebeenusedtorepresentthiskindofsituationinformulae,althoughnotyetinnames.
Fordetails,thereaderisreferredtotheNomenclatureofInorganicChemistry,Chapter6.
Examples1.
FeS2.
Co1_O3.
(Li2,Mg)C124.
Fe105Li365Ti130O63.
4STRUCTURALFORMULAEStructuralformulaegiveinformationaboutthewayatomsinamoleculeorionareconnectedandarrangedinspace.
Exampleso0/001.
OP—0—P—0—P0or(oP—o—P—o—Po)000\000)(C2H5)3Sb\/12.
Pt(C2H5)3Sb"Attemptsmaybemadetorepresentthestructureinthreedimensions.
ExampleClBr3.
/C.
*HCH3Inthisexample,thefulllinesrepresentbondsintheplaneofthepaper,thedottedlinerepresentsabondpointingbelowtheplaneofthepaperandthetriangularbondpointstowardsthereader.
ThiskindofrepresentationwillbediscussedinmoredetailinSection3.
8,p.
21.
10FORMULAEInorganicchemistry,structuralformulaearefrequentlypresentedascondensedformulae.
Thisabbreviatedpresentationisespeciallyusefulforlargemolecules.
Anotherwayofpresentingstructuralformulaeisbyusingbondsonly,withtheunderstandingthatcarbonandhydrogenatomsareneverexplicitlyshown.
ExamplesHHH4.
H—C—C—C—HorCH3-CH2-CH3orHHH5.
H———O—HorCH3-CH2-OHorOH6.
CH3-CH2-CH2-CH2-CH3or7.
orAH2CCH2CHCH2CH2CH8.
orCHCH2-CH2Aswillbeevidentfromtheaboveexamples,andbyextrapolationfromtheruleselicitedforspeciesderivedfromonetypeofatom,thenumbersofgroupsofatomsinaunitandthechargeonaunitareindicatedbymodifiersintheformofsubscriptsandsuperscripts.
Examples9.
C(CH3)10.
CH3-[CH2]5-CH311.
CaCl12.
[{Fe(CO)3}3(CO)2]2Notetheuseofenclosingmarks:parenthesesQ,squarebrackets[]andbraces{}.
Theyareusedtoavoidambiguity.
Inthespecificcaseofcoordinationcompounds,squarebracketsdenotea'coordinationentity'(seebelow).
Intheorganicexamplesabove,theuseofsquarebracketstoindicateanunbranchedchainisshown.
Inorganicnomenclaturegenerallyandininorganicnames,onlytwoclassesofenclosingmarkareused,()and[],withtheparenthesesbeingthejuniorset.
3.
5SEQUENCEOFCITATIONOFSYMBOLSWehavealreadystatedthatthesequenceofatomicsymbolsinanempiricalormolecularformulaisarbitrary,butthatintheabsenceofanyotherrequirementsa11CHAPTER3modifiedalphabeticalsequenceisrecommended.
Thisisprimarilyasequenceforuseinindexes,suchasinabookthatlistscompoundscitedbyformula.
Wheretherearenooverridingrequirements,thefollowingcriteriamaybeadoptedforgeneraluse.
Inaformula,theorderofcitationofsymbolsisbaseduponrelativeelectronegativities.
Althoughthereisnogeneralconfusionaboutwhichof,say,NaandClrepresentsthemoreelectronegativeelement,thereisnouniversalscaleofelectronegativitythatisappropriateforallpurposes.
However,forioniccompounds,cationsarealwayscitedbeforeanions.
Ingeneral,thechoiceisnotsoeasy.
Therefore,theCommissionontheNomenclatureofInorganicChemistryhasrecommendedtheuseofTableIVoftheNomenclatureofInorganicChemistry(Table3.
1ofthisbook)torepresentsuchascalefornomenclaturepurposes.
Theorderofcitationproposedinabinarycompoundisfromtheleastelectronegative(i.
e.
mostelectropositive)tothemostelectronegative,andtheleastelectronegativeelementisthatencounteredlastonproceedingthroughTable3.
1inthedirectionofthearrows.
ThoseelementsbeforeAlareregardedaselectronegative,andthoseafterBaselectropositive.
Ifaformulacontainsmorethanoneelementofeachclass,theorderofcitationwithineachclassisalphabetical.
Note,however,that'acidhydrogen'isalwaysregardedasanelectropositiveelement,andimmediatelyprecedestheanionicconstituentsintheformulaeofacids.
Examples1.
KC14.
O2C1F32.
Na2B4O75.
NaHSO3.
IBrClWhereitisknownthatcertainatomsinamolecularionareboundtogethertoformagroup,aswithSand0in5042_,theseelementscanbesogroupedintheformula,withorwithoutenclosingmarks,dependinguponthecompoundandupontheusers'requirements.
Examples6.
HBr7.
HSO8.
[Cr(H20)6]Cl39.
H[AuCL]Table3.
1Elementsequence.
HeLiBeNeNaMgArKCaKrRbSrXeCsBa1nUirbRa__12SeLa—'LuAc—LrFORMULAETherearevarioussubrules:forexample,asingle-lettersymbol(B)alwaysprecedesatwo-lettersymbol(Be);NH4istreatedasatwo-lettersymbolandislistedafterNe.
Thewrittenalphabeticalorderingofapolyatomicgroupisdeterminedbythefirstsymbolcited:SO42-byS;[Zn(H2O)6]2byZn;NO3-byN,etc.
AmoredetaileddiscussionisgivenintheNomenclatureofInorganicChemistry,Chapter4.
Forbinarycompoundsbetweennon-metals(i.
e.
betweenelementsthatareconsideredtobeelectronegative),amodifiedelectronegativitysequence(cf.
Table3.
1)isadopted,andtheleastelectronegativeelementiscitedfirst.
Thesequenceofincreasingelectronegativityis:RnXeKrArNeHeBSiCSbAsPNHTeSeSAtIBrC1OFForintermetalliccompounds,wherealltheelementscanbeconsideredtobeelectropositive,strictalphabeticalorderingofsymbolsisrecommended.
Examples10.
AuBi11.
NiSn3.
6FORMULAEOFGROUPSWehavealreadymentionedtheformulaeforgroups,suchasS042_,withoutdiscussingtheprinciplesbywhichsuchformulaeareassembled.
Thesemay(ormaynot)involvesomereferencetostructure.
Thegeneralapproachistoselectoneormoreatom(s)asthecentralorcharacteristicatom(s).
Thisissowhethertheionorgroupisacoordinationentityornot.
Thus,Iin1C14,VinVO2andSiandWin[SiW12O40]4areallcentralatomsandarecitedfirst.
Thesubsidiaryatomsthenfollow,inalphabeticalorderofsymbols(thisruleisslightlymodifiedforcoordina-tioncompounds).
Examples1.
[CrO7S]5.
HPO2.
[1C14]6.
SbC12F3.
C107.
PBrCl4.
NOSlightlydifferentrulesapplytocoordinationcompounds,themolecules(or,whencharged,complexions)ofwhichareconsideredtobecomposedofacentralatomtowhicharecoordinatedligandsby(toafirstapproximation)donor—acceptorelectron-pairbonds.
Theligandsaregroupedasformallyanionicorformallyneutral.
Theanionicligandsarecitedfirst(alphabeticalorderoffirstsymbols)andtheneutralligandsnext(alsoinalphabeticalorderoffirstsymbols).
Thewholecoordinationentity(whichmaybepositive,negativeorneutral)isenclosedinsquarebrackets.
OrganicligandsarecitedunderC,andNOandCOareregardedasneutral.
Becausesquarebracketsarealwaysofhighestseniority(orpriority),ahierarchicalsequenceofenclosingmarksisadoptedtoensurethatthisseniorityispreserved:[],etc.
13CHAPTER3Table3.
2Someimportantcompoundclassesandfunctionalgroups.
ClassFunctionalgroupGeneralconstitution*AlkanesNoneCH2÷2AlkenesC=CR2C=CR2(RorArorH)AlkynesCCRCCR(RorArorH)Alcohols-OHR-OHAldehydes0R-CHO(RorAr)—C'2HAmidesoR-CONH2(RorAr)—CNH2Amines-NH2,-NHR,-NR2R-NH2(RorAr)R-NH-RR-NR2Carboxylicacids0R-COOH(RorAr)—C''OHEthers-0-R-O-R(RorAr)EstersoR-COOR(RorAr)—c,,ORHalogenocompounds-F,-Cl,-Br,-IR-F,R-Cl(RorAr)R-Br,R-IKetones>C=OR-CO-R(RorAr)Nitriles-CNR-CN(RorAr)*Inthistable,andincommonorganicusage,Arrepresentsanaromaticgroupratherthantheelementofatomicnumber18,andRrepresentsanaliphaticgroup.
Examples8.
[IrHC12(C5H5N)(NH3)]9.
K3[Fe(CN)]10.
[Ru(NH3)5(N2)]C1211.
K2[Cr(CN)202(02)(NH3)]12.
[Cu{OC(NH2)2}2C12]13.
[1C14]Itisoftenamatterofchoicewhetheraspeciesisregardedasacoordinationentityornot.
Thus,sulfatemayberegardedasacomplexofS"1withfour02_ligands.
Itwouldthenberepresentedas[S04]2,butitisnotconsideredgenerallynecessarytousesquarebracketshere.
Thepositionwithregardto[1C14]isnotsoclear-cut:[1C14],(ICl4)andICl4wouldallbeacceptable,dependingupontheprecisecircumstancesofuse.
14FORMULAEForcertainspeciesitisnotpossibletodefineacentralatom.
Thus,forchainspecies,suchasthiocyanate,thesymbolsarecitedintheorderinwhichtheyappearinthechain.
Examples14.
-SCN17.
-NCS15.
HOCN18.
HCNO16.
(03P0S03)Additioncompoundsarerepresentedbytheformulaeoftheindividualconstitu-entspecies,withsuitablemultipliersthatdefinetheappropriatemolecularratiosoftheconstituentspecies,andseparatedbycentredots.
Ingeneral,thefirstsymbolsdeterminetheorderofcitation.
Examples19.
3CdSO48H2020.
8H2S.
46H2021.
BF32H20Thesesuggestionsareadvisoryandshouldbeusedwheretherearenooverridingreasonswhytheyshouldnotbe.
Forexample,PC13Oisacorrectpresentationbut,becausethegroupP=Opersistsinwholefamiliesofcompounds,thepresentationPOC13maybemoreusefulincertaincontexts.
Thereisnoobjectiontothis.
Theconceptofagroupisespeciallyimportantinorganicchemistry.
Afunctionalgrouprepresentsasetofatomsthatiscloselylinkedwithchemicalreactivityanddefinedclassesofsubstances.
Forinstance,thefunctionalgrouphydroxyl,-OH,ischaracteristicoftheclassesalcohol,phenolandenol.
AlcoholsareoftenrepresentedbythegeneralformulaR-OH,inwhichR-representsahydrocarbongrouptypicalofaliphaticandalicyclicsubstances.
Afunctionalgroupisasetofatomsthatoccursinawiderangeofcompoundsandconfersuponthemacommonkindofreactivity(seeTable3.
2).
PhenolsaregenerallyrepresentedbyAr-OH,inwhichAr-representsanaromaticskeleton,composedofbenzeneringsorsubstitutedbenzenerings.
Enolsaremoleculesinwhichthe-OHgroupislinkedtoanatomthatisalsoengagedinadoublebond.
ExamplesTypicalalcohols22.
OH23.
OHTypicalphenols24.
25.
OH26.
915CHAPTER3Atypicalenol27.
Theformulaediscussedsofarrelyonaminimumofstructuralinformation.
Increasingly,chemistsneedtoconveymorethanalistofconstituentswhenprovid-ingaformula.
Theyneedtosaysomethingaboutstructure;todothis,simplelineformulae(i.
e.
formulaewrittenonasingleline,asistext)needtobemodified.
Howtheyaremodifiedisdeterminedbywhatinformationneedstobeconveyed.
Sometimesthiscantakeasimplemodificationofalineformulatoshowextrabondsnotimmediatelyapparent,asinringcompounds,eitherorganicorcoordinationcompounds.
Examples28.
[NiS={P(CH3)2}(C5H5)]29.
C1CHCH2CH2CH2CH2CH2Notethatthesebondindicatorsdonotimplylongbonds.
Theirsizeandformaredictatedsolelybythedemandsofthelinearpresentation.
Itisusualforacoordinationcompoundtowritetheformulaofaligandwiththedonoratomfirst.
ThenickelcomplexrepresentedabovehasbothSandPbondedtothemetal(aswellasallthecarbonatomsoftheC5H5).
Theringstructureforchlorocyclohexaneshouldbeobvious.
However,inmanycasesitisnotpossibletoshowallthenecessarydetailinalineformula.
Insuchcases,attemptsmustbemadetorepresentstructuresinthreedimensions.
3.
7THREE-DIMENSIONALSTRUCTURESANDPROJECTIONSTheapproachadoptedistoviewthemoleculeinthreedimensions,imaginingeachatomorgrouptobeplacedatavertexofnappropriatepolyhedron.
Inorganicchemistrythisisusuallythetetrahedronwithcarbonatthecentre.
Table3.
3(p.
18)showsthepolyhedranormallyencounteredinorganicandinorganicchemistry.
Italsoincludesforeachpolyhedronthepolyhedralsymbolstodenoteshapeandcoordinationnumber.
Itistobenotedthatthesepolyhedraareoftenpresentedinahighlyformalisedfashion.
Anoctahedronisoftenrepresentedwiththeapicesratherthantheoctahedralfacesdepicted,thus:Anoctahedralcomplex,suchas[Co(NH3)3(N02)3],wouldhaveanacceptoratthecentralpositionandaligandateachofthesixapices,thus:16FORMULAENO2H3N[O2NH3Thisisnotintendedtoindicatebondsbetween,forexample,H3NandNO2,anditisperhapsanunfortunatehybridofathree-dimensionalrepresentationandalineformulainwhichonlyselectedbondsareshown.
Careneedstobeexercisedwhenusingthisformat,anditisnottoberecommended,especiallyforbeginningstudents.
Amoreaccurateandsimplerrepresentationisshownbelow.
NO2INO2H3N—Co—NO2H3NINH3Perspectivecanbeenhancedbyshapingthebondsdirectedoutoftheplaneofthepaper.
NO2,NO2H3NCo'-NO2H3NNH3Normally,atwo-electronbondisrepresentedintheseformulaebyaline.
Whenelectronpairsarenotconvenientlylocalisedbetweenspecificatompairs,itisnotpossibletorepresentbondsso.
Forexample,benzenecanberepresentedas0or,perhaps,moreaccuratelyCIncomplexcompounds,similarrepresentationsareused:C6H5C6H5i,coT'OC—MnMo-COlJ4%OCCOOCCOProjectionsareused,particularlyinorganicchemistry,torepresentthree-dimensionalmoleculesintwodimensions.
InaFischerprojection,theatomsorgroupsofatomsattachedtoatetrahedralcentreareprojectedontotheplaneofthepaperfromsuchanorientationthatatomsorgroupsappearingaboveorbelowthe17CHAPTER3Table3.
3Polyhedralsymbolsandgeometricalstructures.
squareplanarSP-4PolyhedraofJive-coordinationtrigonalbipyramidsquarepyramidPolyhedraofsix-coordinationoctahedrontrigonalprismPolyhedraofseven-coordinationpentagonaloctahedron,facebipyramidmonocappedOCF-7trigonalprism,squarefacemonocappeddodecahedronDD-8hexagonalbipyramidHBPY-8Continued.
18Polyhedraoffour-coordinationtetrahedronT-4TBPY-5SPY-5OC-6TPR-6PBPY-7TPRS-7Polyhedraofeight-coordinationcubesquareantiprismCU-8Table3.
3(Continued.
)FORMULAEoctahedron,trans-bicappedOCT-8trigonalprism,triangularfacebicappedTPRT-8trigonalprism,squarefacebicappedTPRS-8HBPY-9centralatomliebehindtheplaneofthepaper,andthoseappearingoneithersidelieinfront.
Itisveryimportantto'setup'themoleculeinanappropriateconfiguration.
Ifthereisamaincarbonchain,itisalwaysalignedvertically.
acIdCdbThree-dimensionalstructure(a)Fischerprojection(b)Notethatsomeauthoritiesprefertouseathickenedlinetorepresentabondprojectingtowardsthereader,andthatorganicpracticeisnevertoindicateacarbonatominaprojectionbyanatomicsymbol.
ANewmanprojectionisobtainedbyviewingamoleculealongabond.
Taketheethane(orsubstitutedethane)moleculerepresentedbelow(a).
Thisisseeninperspective(b).
e,aIdC—C,-bbfcefThree-dimensionalstructure(a)Perspective(b)Polyhedraofnine-coordinationtrigonalprism,squarefacetricappedheptagonalbipyramidTPRS-9a19CHAPTER3TheNewmanprojectionalongthecentralcarbon—carbonbondisshownbelow.
dNewmanprojectionAcirclerepresentsthesetwocarbonatoms,withlinesfromoutsidethecircletowardsitscentrerepresentingbondstootheratoms.
Thelinesthatrepresentbondstothenearercarbonatomendmeetatthecentre,andthosetotheothercarbonatomendatthecircumference.
Whensuchbondswouldbecoincidentinprojection,theyaredrawnatasmallangletoeachother.
Theexamplesbelowshowprojectionsofeclipsedandstaggeredconformations.
abc'eclipsedstaggeredeclipsedstaggeredThree-dimensionalstructuresNewmanprojectionOtherconformationsencounteredintheliteraturearecategorisedintermsoftheNewmanprojection,asshownbelow.
HHHHHHHHsynperiplanar(sp)synclinal(sc)anticlinal(as)antiperiplanar(ap)orgaucheNotethatthetermssynandantialonearenolongerusedinthiscontext.
Thechlorineatomsmaybedescribedassynperiplanar,synclinal,anticlinaloranti-periplanartoeachother.
Ininorganiccompounds,stereochemicalarrangementsotherthanoctahedralortetrahedralareoftenobserved.
Thesewillbediscussedinmoredetailbelow.
Someselectedrepresentationsofcommonstructuresareshownhere.
Notethatoftenahybridstereoviewofthestructureisused,inwhichsomelinesrepresentbondsandotherstheedgesofthepolyhedronthatdefinestheshape.
Thishasbeendiscussed20afba,CabCb'Clabovefortheoctahedron,andthesamecautionshouldbeusedalsowiththeserepresentations.
ThecentralatomisrepresentedherebytheletterMandtheattachedgroupsbylettersa,b,c,etc.
Foragivenformula(e.
g.
Mabcde)morethanoneshapemaybepossible:CCMM/\abab/dM/Cdc/_____/ababdaCa)Mbc_bCaTIaMbeed—cdc/M/abfda''cb3.
8ISOMERSANDSTEREOISOMERSIsomerismdescribestherelationshipbetweenmolecularentitieshavingthesamemolecularformula,butdifferinginstructureand/orconnectivitybetweentheconstituentatoms.
Forexample,themolecularformulaC7H16correspondstomany21FORMULAECHAPTER3differentalkanesdifferingfromeachotherintheirconnectivities.
Twoareshownin(a)below.
Inthesamemanner,twostructuralformulaecanbeenvisagedforthemolecularformulaC3H60,onebelongingtotheclassofketones,andtheotherbeinganalcohol(b).
(a)and(b)CH3-CO-CH3andCH2=CH-CH2-OHStereoisomersareisomershavingthesamemolecularformulaandthesameconnectivity,butdifferentspatialarrangements.
Therearethreeclassesofstereoisomer:cis—transisomers,conformationalisomersandenantiomers.
3.
8.
1cis—transIsomersTheseareassociatedwithtetrahedralandoctahedralspatialdistributionsofatoms,andwithbonds.
Thestereodescriptorscisandtransindicatethespatialdistributionwithreferencetoaplanedefinedbythemolecularstructure,ofteninrelationtoadoublebond.
ExamplesreferenceplaneCH3CH3CH3H2.
HHH'CH3CH3JCH3H3Ccis-or(Z)-but-2-enetrans-or(E)-cis-5,6-dimethyl-trans-5,6-dimethyl-but-2-enecyclohexa-1,3-cyclohexa-1,3-dienedieneInmanycasesthecis—transstereodescriptorsareambiguousandtheyarenowoftenreplacedbystereodescriptorsEandZ,whichrepresenttherelativesenioritiesofthegroupsattachedtothedoublebond.
TheyareassignedusingtheCahn—Ingold—Prelog(CIP)rules(seetheGuidetoIUPACNomenclatureofOrganicCompounds,pp.
151—154).
Thissystemofsenioritiesisbaseduponrelativeatomicnumbersandisusedinbothorganicandinorganicnomenclatures.
Forotherorganicsystemsofseniority,seeTables4.
10and6.
1andChapter4,Section4.
5.
6(p.
84).
Thecis—transstereodescriptorsareacceptableforsimpleorganicstructuresandtheyhavebeenusedalsotodescribespatialdistributioninoctahedralandsquare-planarstructures.
However,theyarenotadequatetodistinguishallpossibilities.
ThesystemthatiscurrentlyrecommendedforcomplexesisdescribedinmoredetailintheNomenclatureofInorganicChemistry,Chapter10.
223.
8.
2Conformationalisomers(orconformers)FORMULAETheconformationofamoleculeisthespatialarrangementoftheatoms.
Differentstereoisomersthatcanbeinterconvertedbyrotationaboutsinglebondsaretermedconformers.
Thusaconformerisoneofasetofstereoisomersdifferingfromoneanotherintheirconformations,eachofwhichisconsideredtocorrespondtoapotential-energyminimum.
Theinterconversionofconformersbyrotationaroundasinglebondinvolvescrossinganenergybarrierbetweendifferentpotential-energyminima.
ExamplesHsynclinalorgaucheconformationTheconceptofconformationalanalysishasledtoabetterunderstandingofthespatialarrangementsofcyclicalkanesandofthechemicalreactivityoffunctional-izedderivatives.
Aspecificterminologyisused.
Examples3.
envelopeconformation4.
chair5.
boatconformation6.
twist3.
8.
3Inacyclohexaneorsimilarmolecule,extraskeletalbondsareequatorial(b)oraxial(a).
b.
Chiralityisthepropertyofanobjectthatisnotidenticalwithitsmirrorimage.
Forexample,thehumanlefthandhasthesameshapeandinternalstructureasthehumanrighthand,buttheyaredifferentnon-superimposableobjects.
Theyare231.
C'2.
HHHHC'antiperiplanarconformationaEnantiomersCHAPTER3mirrorimagesofeachother.
Wheretwosuchmoleculesexistinchemistry,theyarecalledenantiomers.
Enantiomershaveidenticalphysicalproperties(exceptfortheinteractionwithpolarisedlight)andchemicalreactivity(exceptforreactionwithotherchiralspecies).
Consequently,anybiologicalactivitiesthatinvolvestereospec-ificitymayalsobeverydifferent.
Thedirectionsofthespecificrotationsareequalandopposite.
Achiralmoleculeisnotsuperimposableonitsmirrorimage,whereasanachiralmoleculeis.
Chiralityisduetothepresenceinamoleculeofachiralcentre,axisorplane.
Onlychiralcentreswillbedealtwithhere.
Achiralcentreisanatombindingasetofligandsinaspatialarrangementthatisnotsuperimposableonitsmirrorimage,e.
g.
acarboncompoundCabcd,aphospho-ruscompoundPabcandanammoniumion(Nabcd)±.
ThestereodescriptorsRandSareusedtodescribeeachenantiomer.
TheseareselectedusingtheCIPprioritiesassignedtothesubstituentsa,b,canddbythemethodsdescribedintheGuidetoIUPACNomenclatureofOrganicCompounds,p.
152.
ExampleMirrorplaneH2NNCOOHHOOC.
1CH7CH3H3C1HTwoenantiomersRSWhenamoleculecontainstwochiralcentres,fourorthreestereoisomersarepossible,dependingonwhetherornotaplaneofsymmetryispresent.
Inasetoffourisomers,therearetwopairsofenantiomers.
Isomersthat,arenotenantiomersarecalleddiastereoisomers.
Inthefollowingexample,compoundsIand11areenanti-omersandcompoundsIIIandIVareenantiomers,butcompoundsIandIII,forinstance,arediastereoisomers.
Exampleaaaafbbfbffb2.
ecceecceddddIIIIIIIVAplaneofsymmetrymakesthemoleculeachiralandthusreducesthenumberofisomers.
Themoleculebelowwiththeplaneofsymmetryisdesignatedmeso.
24ExampleMirrorplaneFORMULAEHOOCCOOH3.
HO—J---HIIOHH__hOHHO—I----HHOOCCOOHenantiomersCOOHHOHMirrorHplaneCOOHmesocompoundAmesocompoundhasaspecificrotationofpolarisedlightof00.
Aracemateisanequimolarmixtureoftwoenantiomersanditsspecificrotationisalso0°.
Theexamplesbelowfurtherdemonstratetheuseinorganicnomenclatureofthestereodescriptorsdescribedabove.
ExamplesH\,CH34.
C=C/\H3CH6.
(E)-but-2-enecis-l,2-dimethylcyclohexane8.
(R)-butan-2-olCH3—CH2COOH5.
/\HH(Z)-pent-2-enoicacid6Brtrans-2-bromocyclopentan-l-olH2NH9.
COOH(S)-2-aminopentanoicacid254Namingofsubstances4.
1TYPESOFNOMENCLATURESpecialistsinnomenclaturerecognisetwodifferentcategoriesofnomenclature.
Namesthatarearbitrary(includingthenamesoftheelements,suchassodiumandhydrogen)aswellaslaboratoryshorthandnames(suchasdiphosandLithAl)aretermedtrivialnames.
Thisisnotapejorativeordismissiveterm.
Trivialnomencla-turecontrastswithsystematicnomenclature,whichisanassemblyofrules,them-selvesarbitrary.
Thefunctionofspecialistsinnomenclatureistocodifysuchrulessothateveryonecanusethemtoidentifypuresubstances,ratherlikemanyofususeanalphabettorepresentwords.
Theremaybemorethanonewaytonameacompoundorspecies,andnoonewaymaybesuperiortoalltheothers.
Namesalsovaryincomplexity,dependinguponhowmuchinformationneedstobeconveyed.
Forexample,acompositionalnameconveyslessinformationthanastructural(orconstitutional)name,becausethisincludesinformationaboutthearrangementofatomsinspace.
Chemistshavedevelopednamesformaterialssincethebeginningofthescience.
Initially,thenameswerealwaystrivial,becausethesystematicsofmolecularstructurewerecompletelyunknown.
Thenamesoftheelementsarestillessentiallytrivial,butthesearethebasisofsystematicnomenclature.
Nowthatweunderstandmuchmoreofthewayinwhichatomscombine,wecanconstructnamesthatcangiveinformationaboutstoichiometryandstructure.
However,unsystematicusagesthathavetheirrootsinthedistantpastarestillembeddedinthenomenclature.
Inaddition,thereareseveralsystemsofnomencla-ture,andthesetendtoreflectthekindsofchemistryforwhichtheyhavebeendeveloped.
4.
1.
1Binary-typenomenclatureThisisasystembaseduponstoichiometry.
Itisnotrestrictedtobinary(two-element)compounds,butthenomenclatureisbinaryinstructure,asdiscussedbelow.
4.
1.
2Coordination-typenomenclatureThissystemisadditiveandwasdevelopedoriginallytonamecoordinationcom-pounds,althoughitcanbeusedinothercircumstanceswhenappropriate.
Foradiscussion,seetheNomenclatureofInorganicChemistry,Chapter10.
Thecom-poundtobenamedisconsideredasacentralatomtogetherwithitsligands,andthenameisdevelopedbyassemblingtheindividualnamesoftheconstituents.
Thissystemhasalsobeenappliedtonameoxoacidsandtherelatedanions.
Coordinationnamesforoxoanionsarecitedintheexamplesthroughoutthetext,andtheyarepresentedindetailinSection4.
4.
5(p.
69).
26.
NAMINGOFSUBSTANCES4.
1.
3Substitutive-typenomenclatureThisistheprincipalnomenclaturesystemusedinorganicchemistry,asdescribedintheGuidetoIUPACNomenclatureofOrganicCompounds,p.
18.
Itisbaseduponthenameofaformalparentmolecule(normallyahydride),whichisthensubstituted.
Althoughitisprincipallyanorganicnomenclature,ithasbeenextendedtonamesofhydridesofGroups14,15,16and17.
Thesesystemsmayallbeappliedtothesamecompound.
Thenameadoptedisthenamatterofchoiceorconvenience.
Thus,SiCl4canbenamedsilicontetrachlo-ride(binary),tetrachiorosilicon(coordination)andtetrachlorosilane(substitutive).
Noonenameis'better'or'morecorrect'thananyother.
Otherminorsystemsarealsoinuse.
Somearetraditional,andsomeareveryrestrictedintheirapplication.
Theseincludeacidnomenclature(inorganic,foroxoacidsandderivatives),replacementnomenclature(mainlyorganic,todenotereplacementofskeletalatomsinaparentratherthanreplacementofhydrogenatoms—oxa-azareplacementisonevariant),functionalclassnomenclature(thisisagainprincipallyorganicandinvolvestheuseoftypenamessuchasalcohol,acidandether)andsubtractivenomenclatures(suchasorganic-deoxyandinorganic-debor).
Thesewillallbereferredtobrieflyasappropriate.
4.
2BINARY-TYPENOMENCLATUREAlthoughitispossibletodevelopanamebasedsimplyonanempiricalformula(areasonableproposalmightbecalciumsulfurtetraoxygenforCa504),thisisneverdone.
Binarynomenclatureisprincipallyinorganic,andhasnorealsimpleorganiccounterpart.
4.
2.
1BasisofthebinarysystemThisprovidesnamesforcompoundsforwhichlittleornostructuralinformationisavailable.
However,aminimumofstructuralinformationisknownorassumed.
Inparticular,usingtheassumedorestablisheddivisionofconstituentsintopositiveandnegativepartsalreadyemployedaboveinestablishingformulae,wedividetheconstituentsintothesametwoclasses,hencetheterm'binarynomenclature'.
Thepositiveandnegativepartsaresometimesreferredtoaselectropositiveandelectronegative.
However,thereisnogeneralscaleofelectropositiveness,andconstituentsarereallymoreorlesselectronegativeandaredividedintogroupsofgreaterandlesserelectronegativity.
AsdiscussedinChapter3onformulae,eventhisisnottobeinterpretedwithtoomuchrigidity,andinnomenclaturevariousarbitrarydevicesareusedtodefineelectronegativity.
Weshallcontinuetousethetermselectropositiveandelectronegativebecausetheyaresanctionedbylongnomencla-tureusage.
Innocircumstancesshouldnumericalvaluesbeappliedtosuchterms.
4.
2.
2NamederivationThenameisderivedbycombiningthenamesoftheelectropositiveconstituent(s)withthoseoftheelectronegativeconstituent(s),suitablymodifiedbyanynecessary27CHAPTER4multiplicativeprefixes.
Theelectropositiveconstituentnamesarecitedfirst,andareseparatedfromtheelectronegativeconstituentnamesbyaspace.
Themultiplicativeprefixesmaynotbenecessaryiftheoxidationstatesareexplicitorareclearlyunderstood.
However,oxidationstateinformationshouldneverbeconveyedbythesuffixes-ousand-ic.
Thisisconfusinginthenamesofcomplexes(compareferrouswithcuprousandferricwithcupric,wherethesamesuffiximpliesdifferentoxidationstates).
Theoxidationstateshouldalwaysbeexplicitanddesignatedbyromannumerals.
Namesofacids,suchassulfurousandnitrous,andsulfuricandnitric,presentthesameproblem.
Here,coordinationnamesarealsopreferredandtherearenumerousexamplesthroughoutthetext.
Examples1.
NaC1sodiumchloride2.
Ca3P2calciumphosphide3.
FeOtriirontetraoxideThenameoftheelectropositiveconstituentissimplytheunmodifiedelementname,thenameofapolyatomiccationoranacceptedgroupname,asappropriate.
Examples4.
NHClammoniumchloride5.
UOCluranyldichloride6.
02[PtF6]dioxygenhexafluoroplatinate7.
OF2oxygendifluoride8.
NOHSO4nitrosylhydrogensulfateIfthereismorethanoneelectropositiveconstituent,thenamesshouldbespacedandcitedinalphabeticalorderoftheinitialletters,orofthesecondlettersifthefirstlettersarethesame.
Multiplicativeprefixesareignoredforpurposesofordering.
Hydrogenisanexception.
Itisalwayscitedlastamongtheelectropositiveconstituentsandisseparatedfromthefollowinganionnamesbyaspaceunlessitisknowntobeboundtotheanion.
InlanguagesotherthanEnglish,differentorderingmayapply.
Intheexamples,thelettersdefiningtheorderareinboldfaceforclarity.
Thisshouldnotbeextendedtonormalpractice.
Examples9.
KMgC13magnesiumpotassiumchloride10.
NaNHHPOammoniumsodiumhydrogenphosphate11.
Cs3Fe(C204)3tricaesiumirontris(oxalate)12.
A1K(S04)2.
12H20aluminiumpotassiumbis(sulfate)—water(l/l2)Thislastexampleshowshowtheformulaofacompoundconsideredasanadditioncompoundisconvertedtoaname.
Themolecularproportionsareshownastheappropriateratio(here,1/12)inparenthesesafterthenames,whichareseparatedbyalongdash.
Thenamesofmonoatomicelectronegativeconstituentsarederivedfromthenamesoftheelements,butmodified.
Theterminationisreplacedbytheanion28NAMINGOFSUBSTANCESdesignator-ide.
Thereasonwhythetreatmentofthesenamesisdifferentfromthatforelectropositiveconstituentsishistorical,andhasnoobviouslogicalbasis.
Incertaincases,themodificationisaccompaniedbyanabbreviationandthereareafewanionnamesthatarebasedonLatinroots,althoughtheelementnamesarebasedonEnglish.
AllthesenamesaregiveninTable4.
1.
Ifthereismorethanoneelectronegativeconstituentthenamesareorderedalphabetically,aswiththeelectropositivenames.
Examples13.
KC1potassiumchloride14.
BBrF2boronbromidedifluoride15.
PC13Ophosphorustrichlorideoxide16.
Na2F(HCO3)disodiumfluoridehydrogencarbonateNotethatinthelastexample,'disodium'isequallyasacceptableas'sodium',butinmostcircumstancesthedi-wouldbeassumedtobeobvious.
Thenamehydrogen-carbonate(nospace)impliesthatthehydrogenisbondedinsomefashiontothecarbonatefragment.
Thepresenceofaspacewouldimplythatitisnot.
Thenamesofpolyatomicelectronegativegroupsarederivedinvariousways.
Homoatomicspeciesaredesignatedusinganappropriatemultiplicativeprefix.
Examples17.
(Sn9)4nonastannide18.
(13)triiodide19.
S22_disulfideNotethatuponformingafullname—asinNa4Sn9,tetrasodium(nonastannide)andTl(I3),thallium(triiodide)—enclosingmarksmaybeusefultoavoidambiguity.
ComparewithT1I3,thalliumtriiodide.
Insomecircumstances,suchaswhenthenameoftheelectronegativespeciesiscitedalone,e.
g.
inthediscussionofananion,itmaybeusefultoindicatethecharge:Sn94,nonastannide(4—);(I3),triiodide(1—);522_,disulfide(2—).
Thisisdiscussedfurtherbelow.
Sometrivialnamesarestillallowed.
Examples20.
02superoxide21.
022_peroxide22.
O3ozonide23.
N3azide24.
C22acetylideThenamesofheteroatomicelectronegativeconstituentsgenerallytaketheanionending-ate,whichisalsocharacteristicofthenamesofanionsofoxoacids(sulfate,phosphate,nitrate,etc.
).
Manysuchanionsarecoordinationcompounds,andthesenamesareassembledusingtherulesofcoordinationnomenclature(seeSection4.
4,p.
51).
29aluminiumarsenicAsH4arsoniumAs033arsenitetrioxoarsenate(3—)trioxoarsenate(m)As043arsenatetetraoxoarsenate(3—)tetraoxoarsenate(v)AsS43tetrathioarsenate(3—)tetrathioarsenate(v)auridearsenito(3—)trioxoarsenato(3—)trioxoarsenato(iii)arsenato(3—)tetraoxoarsenato(3—)tetraoxoarsenato(v)tetrathioarsenato(3—)tetrathioarsenato(v)Table4.
1Namesofionsandgroups.
*NameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandAgsilversilverargentidealuminidearsenideAlaluminiumAs(mono)arsenicAsH4As03As04AsS4AugoldT1arsenidoAugold(l+)gold(i)Au3+gold(3÷)gold(iii)B(mono)boronboronborideboridoB02(BOf)metaboratepoly[dioxoborate(l—)}poly[dioxoborate(iii)]metaboratoB03B033boratetrioxoborate(3—)trioxoborate(m)boratotrioxoborato(3—)trioxoborato(iii)BabariumbariumbarideBeberylliumberylliumberyllideBr(mono)brominebrominebromidebromoBrObrominemonoxidebromosylBr0oxobromate(1—)oxobromato(l—)oxobromate(i)(nothypobromite)oxobromato(i)Br02brominedioxidebromylBrOfdioxobromate(l—)dioxobromato(l—)dioxobromate(iii)(notbromite)dioxobromato(iii)Br03brominetrioxideperbromylBr03trioxobromate(l—)trioxobromato(l—)trioxobromate(v)(notbromate)trioxobromato(v)Br04brominetetraoxideBr04tetraoxobromate(l—)tetraoxobromato(l—)tetraoxobromate(vii)(nottetraoxobromato(vii)perbromate)Br3tribrominetribromide(1—)tribromo(l—)C(mono)carboncarboncarbidecarbidoCNCNcyanidecyanoCOcarbonmonoxidecarbonylcarbonylcarbonmonoxideCO3C032carbonatecarbonatotrioxocarbonate(2—)trioxocarbonato(2—)trioxocarbonate(iv)trioxocarbonato(iv)CScarbonmonosulfidethiocarbonylthiocarbonylcarbonmonosulfideCT1CS3C532trithiocarbonate(2—)trithiocarbonato(2—)trithiocarbonate(iv)trithiocarbonato(iv)C2dicarbonC22acetylidedicarbide(2—)dicarbidoCl(mono)chlorinechlorinechloridechloroContinuedonp.
32.
tetrafluorochlonne(l÷)tetrafluorochlonne(v)chiorosylcuriumCo2+cobalt(2+)cobalt(ii)Co3+cobalt(3+)cobalt(iii)Cr2+chromium(2+)chromium(ii)Cr3+chromium(3+)chromium(iii)tetrafluorochlorate(l—)tetrafluorochlorate(iii)C10hypochioriteoxochlorate(l—)oxochlorate(i)ClOfchloritedioxochlorate(l—)dioxochlorate(iii)C103chloratetrioxochlorate(l—)trioxochlorate(v)C104perchioratetetraoxochlorate(l—)tetraoxochlorate(vn)curidecobaltidehypochloritooxochlorato(l—)oxochlorato(i)chioritodioxochlorato(l—)dioxochlorato(iii)chloratotrioxochlorato(l—)trioxochlorato(v)perchloratotetraoxochlorato(l—)tetraoxochlorato(vii)Table4.
1(Continued.
)NameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandC1F4chlorinetetrafluorideClF4C1F4T1tetrafluorochlorato(l—)tetrafluorochlorato(iii)chlorylperchlorylClOchlorinemonoxideCl02chlorinedioxideC103chlorinetrioxideC104chlorinetetraoxideCmcuriumCocobaltCrchromiumchromideCr02chromiumdioxidechromylCr04Cr042chromatechromatotetraoxochromate(2—)tetraoxochromato(2—)tetraoxochromate(vi)tetraoxochromato(vi)Cr207Cr2072dichromate(2—)dichromato(2—)t-oxo-hexaoxodichromate(2--)jt-oxo-hexaoxodichromato(2—)j.
t-oxo-hexaoxodichromate(vi)g.
t-oxo-hexaoxodichromato(vi)CucopperCu+cupridecopper(1+)copper(i)Cu2+copper(2+)copper(ii)F(mono)fluorinefluorinefluoridefluoroFeironFe2+ferrideiron(2+)iron(ii)Fe3+iron(3÷)iron(nl)H(mono)hydrogenhydrogenhydridehydridohydro(inboroncompounds)HCO3HC03hydrogencarbonate(1—)hydrogencarbonato(1—)zhydrogentrioxocarbonate(1—)hydrogentrioxocarbonato(1—)hydrogentrioxocarbonate(iv)hydrogentrioxocarbonato(iv)HOHOHO0HhydroxylhydroxyliumhydroxidehydroxidoC)hydroxoCHO2hydrogendioxidehydrogenperoxide(1+)HOfhydrogenperoxide(1—)hydrogenperoxohydrogendioxide(1—)HPO4HP042hydrogenphosphate(2—)hydrogenphosphato(2—)hydrogentetraoxophosphate(2—)hydrogentetraoxophosphato(2—)hydrogentetraoxophosphate(v)hydrogentetraoxophosphato(v)C,,Continuedonp.
34.
H20oxidanewaterH30trihydrogenoxideH2P04Hg2mercury(2÷)mercury(u)ij2+dimercury(2+)dimercury(i)iodineTE'+4tetrafluoroiodine(1+)tetrafluoroiodine(v)hydrogensulfide(l—)HS03hydrogensulfite(l-.
)hydrogentrioxosulfate(l—)hydrogentrioxosulfate(iv)HS04hydrogensulfate(l—)hydrogentetraoxosulfate(l—)hydrogentetraoxosulfate(vi)H2P04'dihydrogenphosphate(l—)dihydrogentetraoxophosphate(l—)dihydrogentetraoxophosphate(v)mercuridehydrogensulfido(l—)sulfanidohydrogensulfito(l—)hydrogentrioxosulfato(l—)hydrogentrioxosulfato(iv)hydrogensulfato(l—)hydrogentetraoxosulfato(l—)hydrogentetraoxosulfato(vi)aquaoxidaneTable4.
1(Continued.
)NameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandHSHSHSO3HSO4riT1H3OoxoniumHgmercuryI(mono)iodineIF4iodinetetrafluoride10iodineoxidedihydrogenphosphato(l—)(1—)iodosyliodide1F4tetrafluoroiodate(l—)tetrafluoroiodate(iii)10-oxoiodate(l—)oxoiodate(i)(nothypoiodite)iodotetrafluoroiodato(l—)tetrafluoroiodato(iii)oxoiodato(l—)oxoiodato(i)102iodinedioxideiodylIOfdioxoiodate(l—)dioxoiodato(l—)dioxoiodate(iii)(notiodite)dioxoiodato(iii)103iodinetrioxideperiodylIOiodateiodatotrioxoiodate(l—)trioxoiodato(l—)trioxoiodate(v)trioxoiodato(v)104iodinetetraoxide104periodateperiodatotetraoxoiodate(1—)tetraoxoiodato(l—)tetraoxoiodate(vii)tetraoxoiodato(vu)106I06hexaoxoiodate(5—)hexaoxoiodato(5—)hexaoxoiodate(vii)hexaoxoiodato(vii)13triiodinetriiodide(l—)triiodo(l—)InindiumindiumindideIriridiumiridiumiridideKpotassiumpotassiumkalideLilithiumlithiumlithideMgmagnesiummagnesiummagnesideMnmanganeseMn2+manganidemanganese(2+)manganese(ii)Mn3manganese(3+)manganese(m)Mn04Mn04permanganatepermanganatotetraoxomanganate(l—)tetraoxomanganato(l—)tetraoxomanganate(vii)tetraoxomanganato(vii)Mn042manganatemanganatotetraoxomanganate(2—)tetraoxomanganato(2—)tetraoxomanganate(vi)tetraoxomanganato(vi)MomolybdenummolybdenummolybdenideC')N(mono)nitrogennitrogennitridenitridoContinuedonp.
36.
NCO(seeOCN)NHNH3azaneammoniaNH4NOnitrogenmonoxideNO2nitrogendioxideNO3nitrogentrioxideNH3ammoniumylazaniumylNH4ammoniumazaniumhydroxyamidoamidoazanidoammineazanenitrosylnitrogenmonoxidenitronitrito-Odioxonitrate(iii)dioxonitrato(iii)dioxonitrate(2—)dioxonitrato(2—)dioxonitrate(ii)(notnitroxylate)dioxonitrato(ii)nitratoTable4.
1(Continued.
)NameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandNHOHNH2ritTlNH2imideazanediideazanide(2—)NHOWhydroxyamideNHfamideazanideimidoazanediidonitrosylN0nitrylnitroyloxonitrate(l—)oxonitrate(i)NOfnitritenitrito-Ndioxonitrate(l—)dioxonitrato(l—)N03nitratetrioxonitrate(l—)trioxonitrate(v)trioxonitrato(l—)trioxonitrato(v)N2HN2HN2WdiazyniumdiazenidediazenidoN2H3diazanetriidediazanetriidodiazanide(3—)hydrazido(3—)hydrazinetriidehydrazinide(3-)hydrazide(3—)N2H2diazeneN2H22+N2H22diimidediazynediiumdiazanediidediazanediidodiazynium(2+)hydrazide(2—)hydrazido(2—)diazanide(2—)hydrazinediideN2H2diazenediimideNHNH2N2H3N2H3diazeniumhydrazidehydrazidodiazanidediazanidohydrazinideN2H4diazaneN2H42+hydrazinehydrazinediazenediiumdiazanediazenium(2+)N2H5N2H5hydrazinium(1+)hydraziniumdiazaniumr2+26hydrazinium(2+)diazanediiumdiazanium(2+)hydrazinediiumN202dinitrogendioxideN2022dioxodinitrate(N—N)(2—)dioxodinitrato(N—N)(2—)dioxodinitrate(N—N)(i)(notdioxodinitrato(N—N)(i)hyponitrite)N3trinitrogentrinitrogenazideazidotrinitride(1—)trinitrido(1—)NasodiumsodiumnatrideCl)Continuedonp.
38.
OH(seeHO)Ni2nickel(2+)nickel(ii)Ni3nickel(3÷)nickel(iii)oxygenoxidecyanatenitridooxocarbonate(l—)nitridooxocarbonate(iv)oxooxidocyanatocyanato-Ocyanato-Nnitridooxocarbonato(l—)nitridooxocarbonato(iv)T103trioxygenozonefulminatecarbidooxonitrate(l—)carbidooxonitrate(v)r2—'—'2peroxidedioxide(2—)02hyperoxidesuperoxidedioxide(l—)Oozonidetrioxide(l—)fulminatocarbidooxonitrato(l—)carbidooxonitrato(v)peroxodioxido(2—)hyperoxosuperoxidodioxido(l—)02dioxygenozonidotrioxido(l—)03trioxygenTable4.
1(Continued.
)NiNameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandnickel0(mono)oxygenOCNnickelideONC02dioxygen'-'2dioxygen(l+)OsosmiumosmiumosmideP(mono)phosphorusphosphorusP3phosphidephosphidoPCi4phosphorustetrachioridePCl4tetrachiorophosphoniumtetrachlorophosphate(1—)tetrachlorophosphato(1—)tetrachlorophosphonium(v)tetrachiorophosphate(iii)tetrachiorophosphato(iii)tetrachlorophosphorus(l-i-)tetrachiorophosphorus(v)tetrachlorophosphanium(1+)PHO3PH032phosphonatephosphonato(2—)hydndotrioxophosphate(2—)hydridotrioxophosphato(2—)PH202PH2Ofphosphinatephosphinatodihydridodioxophosphate(1—)dihydridodioxophosphato(1—)PH4PH4phosphoniumP0phosphorusmonoxidephosphorylP03P033phosphitephosphito(3—)trioxophosphate(3—)trioxophosphato(3—)trioxophosphate(iii)trioxophosphato(in)(PO3)metaphosphatepoiy[trioxophosphate(1—)]poly[trioxophosphate(v)]P04P043zphosphatephosphato(3—)orthophosphateorthophosphatotetraoxophosphate(3—)tetraoxophosphato(3—)tetraoxophosphate(v)tetraoxophosphato(v)P207diphosphorusP2074heptaoxidediphosphate(4—)diphosphato(4—)i-oxo-hexaoxodiphosphate(4—)ji-oxo-hexaoxodiphosphato(4--)t-oxo-hexaoxodiphosphate(v)g.
t-oxo-hexaoxodiphosphato(v)PbleadPb2plumbidelead(2+)iead(ii)C)Pb4T1lead(4+)lead(iv)Continuedonp.
40.
Table4.
1(Continued.
)S(mono)sulfurSCNSOsulfurmonoxideSO2sulfurdioxidePd2palladium(2+)palladium(ii)Pd4palladium(4+)palladium(iv)platinum(2÷)platinum(ii)platinum(4+)platinum(iv)rubidiumrubididerheniumrhenidesulfinylthionylsulfonylSO22_Re04tetraoxorhenate(l—)tetraoxorhenate(vii)(notperrhenate)Re042tetraoxorhenate(2—)tetraoxorhenate(vi)(notrhenate)sulfuryldioxosulfate(2—)dioxosulfate(ii)(notsulfoxylate)tetraoxorhenato(l—)tetraoxorhenato(vn)tetraoxorhenato(2—)tetraoxorhenato(vi)sulfidothiothiocyanato-Nthiocyanato-Snitridothiocarbonato(l—)nitridothiocarbonato(iv)sulfurmonoxidedioxosulfato(2—)dioxosulfato(ii)SO2sulfurdioxidePdpalladiumNameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandpalladidePtplatinumRbrubidiumRerheniumRe04platinidesulfursulfidethiocyanatenitridothiocarbonate(l—)nitridothiocarbonate(iv)SO3sulfurtrioxideS032sulfitesulfitotrioxosulfate(2—)trioxosulfato(2—)tnoxosulfate(iv)trioxosulfato(iv)SO4sulfurtetraoxideS042sulfatesulfatotetraoxosulfate(2—)tetraoxosulfato(2—)tetraoxosulfate(vi)tetraoxosulfato(vi)SO5SO5trioxoperoxosulfate(2—)trioxoperoxosulfate(vi)(notperoxomonosulfate)52disulfurS22disulfide(2—)disulfido(2—)S203disulfurtrioxide52032_thiosulfatethiosulfatotrioxothiosulfate(2—)trioxothiosulfato(2—)trioxothiosulfate(vi)trioxothiosulfato(vi)S204S2042_dithionitedithionitotetraoxodisulfate(S—S)(2--)tetraoxodisulfato(S—S)(2—)tetraoxodisulfate(S—S)(iii)tetraoxodisulfato(S—S)(iii)S205disulfurpentaoxidedisulfurylS2052_t-oxo-tetraoxodisulfate(2—)jt-oxo-tetraoxodisulfate(iv)(notdisulfite)S20-iS2072_disulfate(2—)disulfato(2—)Zt-oxo-hexaoxodisulfate(2—)i-oxo-hexaoxodisulfato(2--)C)ii-oxo-hexaoxodisulfate(vi)t-oxo-hexaoxodisulfato(vi)Cc2-208i-peroxo-hexaoxodisulfate(2—)jt-peroxo-hexaoxodisulfate(vi)(notperoxodisulfate)Sb(mono)antimonyantimonyantimonideantimonidoSbH4SbH4stiboniumContinuedonp.
42.
Te06Sn2+tin(2+)tin(ii)Sn4+tin(4+)tin(iv)Se042tetraoxoselenate(2—)tetraoxoselenate(vi)(notselenate)suicide(SiO32imetasilicatepoly[trioxosilicate(2—)]poly[trioxosilicate(iv)}Si044orthosilicatetetraoxosilicate(4—)tetraoxosilicate(iv)Si2076t-oxo-hexaoxo-disilicate(6—)i-oxo-hexaoxo-disi1icate(iv)stannideTe066hexaoxotellurate(6—)hexaoxotellurate(vi)(notorthotellurate)tetraoxoselenato(2—)tetraoxoselenato(vi)silicidohexaoxotellurato(6—)hexaoxotellurato(vi)Table4.
1(Continued.
)NameNeutralatomorUncharged(atom,groupformulamoleculeorradical)CationorcationicgroupAnionLigandsiliconT1Se04Si(mono)siliconSi03Si04Si207SntinTe(mono)telluriumTe03Te04telluriumtelluridotellurideTe032trioxotellurate(2-)trioxotellurate(iv)Te042tetraoxotellurate(2—)tetraoxotellurate(vi)TititaniumtitaniumtitanideTiOtitaniummonoxideoxotitanium(Iv)TithalliumthalliumthallideUuraniumuraniumuranideU02uraniumdioxideUO2uranyl(l+)uranyl(v)dioxouranium(l÷)dioxouranium(v)U022+uranyl(2+)uranyl(vi)dioxouranium(2+)dioxouranium(vi)VvanadiumvanadiumvanadideVOvanadiummonoxideoxovanadium(iv)WtungstentungstentungstideZnzinczinczincideZrzirconiumzirconiumzirconideZrOzirconiummonoxideoxozirconium(iv)*Thistablecontainsfivecolumns,thefirstofwhichcontainsthesymbolorformulaoftheneutralatomorgroup.
Thesecondcolumncontainsthecorrespondingname.
Thethirdcolumncontainsthenamecorrespondingtothesymbolorformulawhenitcarriesoneormoreunitsofpositivecharge.
Inorganicnomenclatureallowschargestoberepresentedbythechargenumber,ortobeinferredfromanappropriateoxidationnumber.
Bothmethodsaredisplayedinthethirdcolumnandinthesucceedingcolumns.
Formulaeforionsareshownforcaseswhereitisfeltthatconfusionmightotherwisearise.
Thefourthcolumncontainsthenameofthesymbolorformulawhenitcarriesoneormoreunitsofnegativecharge.
Finally,thefifthcolumncontainsthenameoftheformulaorsymbolwhenthespeciesitrepresentsisaligand(usuallyassumedtobeanionicifitisnotneutral).
Thesymbols(formulae)arelistedinalphabeticalorderaccordingtotheprinciplesoutlinedabove.
Becausetheterminations-ousand-icformetalcationnamesarenolongerrecommended,thesehavebeenexcluded,butwehaveattemptedtoincludeallthosetraditionalnamesthatarestillallowed.
Wehavenotattemptedtopresentnamesforspeciesofveryrareorunlikelyoccurrence,sotherearegapsinthecolumns.
Usersshouldnotethatwenameonlyonespecificstructureforagivenformula.
Insomecasestheremaybeotherstructuresthatwehavenotnamedcorrespondingtothatformula.
rI)-1(JT1CPACHAPTER4Examples25.
[Fe(CO)4]2tetracarbonylferrate(2—)26.
[Cr(NCS)4(NH3)2Jdiamminetetrathiocyanatochromate(1—)27.
so32-trioxosulfate(2—),preferredtosulfite28.
NO2-dioxonitrate(l—),preferredtonitriteSometraditionalnames(oftenwithout-ateendings)arestillallowed,althoughsystematiccoordinationnamesaregenerallypreferred.
Examples29.
CNcyanide30.
NH2amide31.
OH-hydroxide32.
As033arsenite33.
ClOchlorite34.
C10hypochlorite35.
NO2-nitrite36.
5032sulfite37.
SOdithioniteTheorderofcitationwithinclassesisalwaysalphabetical.
Theuseofmultiplicativeprefixesdoesnotaffectthisorderunlesstheprefixispartofthename:again,comparetriiodideand(triiodide).
Twosetsofmultiplicativeprefixesaregenerallyused(seeTable4.
2).
Iftwosuccessivemultiplicativeprefixesarerequired,theGreek-basedprefixesarerecommendedtobeemployedinthemannershown:Ca(13)2,calciumbis(triiodide).
Whereitisrequiredtoindicateoxidationstateand/orcharge,theformerisindicatedbyusingaromannumeral(inparentheses)asasuffix,andthelatterbyusinganarabicnumeralfollowedbythechargesign(allinparentheses)alsoasasuffix.
Table4.
2Numericalprefixes.
1Mono19Nonadeca2Di(bis)20Icosa3Tn(tris)21Henicosa4Tetra(tetrakis)22Docosa5Penta(pentakis)23Tricosa6Hexa(hexakis)30Triaconta7Hepta(heptakis)31Hentriaconta8Octa(octakis)35Pentatriaconta9Nona(nonakis)40Tetraconta10Deca(decakis),etc.
48Octatetraconta11Undeca50Pentaconta12Dodeca52Dopentaconta13Trideca60Hexaconta14Tetradeca70Heptaconta15Pentadeca80Octaconta16Hexadeca90Nonaconta17Heptadeca100Hecta18Octadeca44NAMINGOFSUBSTANCESExamples38.
UO2239.
Na40.
PO341.
N2042.
Fe30443.
SF644.
UO2SO45.
(UO)2SO46.
Hg2Cl247.
Fe(SO)3uranyl(vi)ordioxouranium(2+)natride(—i)phosphate(v)nitrogen(i)oxideiron(ii)diiron(iii)tetraoxidesulfur(vi)fluorideuranyl(2+)sulfateordioxouranium(vi)tetraoxosulfate(vi)uranyl(1+)sulfateorbis[dioxouranium(v)]tetraoxosulfate(vi)dimercury(i)chlorideiron(3+)sulfateoriron(iii)sulfateorevendiirontrisulfateQualificationbybothchargenumberandoxidationnumberisnotallowed.
Itshouldbeevidentthatthereareseveralwaysofconveyingthesamestoichiometricinforma-tion,employingchargenumber,oxidationnumberandmultiplicativeprefixes.
Employingthemallwouldcreateredundancies.
Ingeneral,oneuseswhicheverdevicesarebothnecessaryandsufficient,andnomore.
Thenamesdescribedherecanbeusedtodevelopfurthernameswithalittlemoremanipulation.
Additioncompounds(atermthatcoversdonor—acceptorcomplexesaswellasavarietyoflatticecompounds)ofuncertainstructurecanbenamedbycitingthenamesoftheconstituentcompoundsandthenindicatingtheirpropor-tions.
Hydratesconstitutealargeclassofcompoundsthatcanberepresentedbythismeans.
Examples48.
3CdSO48H2049.
CaCl8NH50.
BiCl33PCl551.
Al2(504)3.
I(SO24H20cadmiumsulfate—water(3/8)calciumchloride—ammonia(1/8)bismuth(m)chloride—phosphorus(v)chloride(1/3)aluminiumsulfate—potassiumsulfate—water(1/1/24)Becausethebasicsystemdescribedentailstheconsiderationofthenamesofindividualelectropositiveandelectronegativesubstituents,itrequireslittleelabora-tion(andthisisimpliedinthetextabove)tousethesameprinciplestonamebothanionsandcations,andhencealsosalts.
However,thebinarynamesusedheredonotnecessarilyimplysalt-likecharacter.
Thenamesofcationscanbedesignatedquitesimply,althoughitisabsolutelynecessarytospecifycharge,eitherdirectlyusingchargenumberorindirectlyusingoxidationnumber.
Theparenthesesintheseexamplesofformulaeareoptional.
Examples52.
Na53.
U54.
I55.
(O)56.
(Bi5)457.
(Hg)2sodium(1+)ionorsodium(i)cationuranium(6+)ionoruranium(vi)cationiodine(l+)ionoriodine(i)cationdioxygen(l+)ionpentabismuth(4+)iondimercury(2+)ionordimercury(i)cation45CHAPTER4Cationscanalsobeobtainedbytheformaladditionofahydron(hydronistherecommendednameforthenormalisotopicmixtureofprotons,deuteronsandtritons,seep.
7)toabinaryhydride.
Insuchcases,aformalismofsubstitutivenomenclatureisused;thesuffix-iumisaddedtothename,slightlymodified,oftheparenthydride.
TheselectionofpermittedhydridenamesandtheirusagearediscussedinSection4.
5onsubstitutivenomenclature.
Examples58.
H3Ssulfanium59.
PHphosphanium60.
SiH5silaniumSomevariantsarealsoallowedformononuclearcationsofGroups15,16and17.
Thesearebasedontheusageofsubstitutivenomenclature,wheretheformaladditionofahydrontoaparenthydridetogiveacationisrepresentedbythesuffix-onium.
Examples61.
PH4phosphonium62.
AsH4±arsonium63.
SbH4stibonium64.
H30±oxonium65.
H3Ssulfonium66.
H2IiodoniumThenameammoniumforNH4isnotstrictlysystematic,butishallowedbylongusageandisthereforealsoallowed.
Derivativesofthesehydrides,includingorganicderivatives,arenamedusingtherulesofsubstitutivenomenclature,orbyusingcoordinationnomenclature,asseemsmoreappropriate.
Examples67.
[PCl4]tetrachlorophosphoniumionortetrachlorophosphorus(1+)68.
[P(CH3)2Cl2]dichlorodimethylphosphoniumionordichlorodimethylphosphorus(1+)Wherethecationcanclearlyberegardedasacoordinationcomplex,coordinationnomenclature(seep.
51)isthenaturalchoice.
Example69.
[CoCl(NH3)5]2pentaamminechlorocobalt(2+)ionTheseapplicationswillbediscussedfurtherbelow.
Thereareafewspecialcaseswheretrivialnamesareallowed.
Somearelistedhere.
46NAMINGOFSUBSTANCESExamples70.
NOnitrosylcation71.
OHhydroxyliumcation72.
NO2nitrylcation73.
UO2uranyl(2+)cationThenamesofanionssimilarlyareobtainedbyanextensionofthenamesusedforelectronegativeconstituents,butwiththeprovisothattheendingisalwayscharac-teristicofananion(ide,-ateor-ite,asdiscussedabove).
Forthenamesofmonoatomicanions,seeTable4.
1.
Homopolyatomicanionstakenamesofthekindexemplifiedbelow.
Examples74.
02dioxide(l—)75.
I3triiodide(1—)76.
Pb94-nonaplumbide(4—)Anionsobtainedformallybylossofahydronfromaparenthydride(seeTable5.
2p.
99foralistofparenthydridenames)areconvenientlynamedbythemethodsofsubstitutivenomenclature.
Examples77.
CHmethanide78.
NH2amideorazanide79.
PH2-phosphanediideorhydrogenphosphide(2—)80.
SiH3silanideAnionscanalsobeformedbythelossofhydronsfromacids.
Wherealltheavailablehydronsarelost,theacidnameismodifiedasshownbelow.
Examples81.
H2504,sulfuricacid—S042,sulfate82.
H3P04,phosphoricacid—÷P043,phosphate83.
CH3COOH,aceticacid—CH3COO,acetateInsomecases,itmaybenecessarytoaddthechargetothenametodistinguishdifferentoxidationstatesordegreesofoxygenation(seealsoSection4.
4.
5,p.
69).
Inmostcases,coordinationnamesarepreferredforsuchspecies.
Ifnotalltheacidhydronsarelost,thesituationisrathermorecomplex.
Examples84.
HS04hydrogensulfate(1—)85.
H2P04dihydrogenphosphate(1—)The-ateterminationisalsousedwhenhydronsaresubtractedformallyfromanOHgroupinalcohols,etc.
47CHAPTER4Examples86.
CH30methanolate87.
C6H5SbenzenethiolateAnalternativewayofenvisaginghydrideformationisbyreactionofaneutralmoleculewithH-,hydrideion.
The-ateterminationisagainused.
Examples88.
BH4tetrahydroborate89.
PH6-hexahydridophosphate90.
BC13WtrichlorohydroborateNotethatcertainoxoanionsstillretaintrivialnamesandthesearelistedinTable4.
1.
Notealsotheexceptionaluseof'hydro'insteadoftheusual'hydrido'torepresenttheboundhydrideion.
Thisisrestrictedtoboronnomenclatureandsurvivesforhistoricalreasons.
Havingestablishedthemethodsfornaminganionsandcations,itisclearthatsaltshavebinary-typenamesthatareoftenindistinguishablefromthebinarynameassignedbydividingtheconstituentsintoelectropositiveandelectronegativespecies.
ThenamesofcationsalwaysprecedethenamesofanionsinEnglishandthenamesarealwaysseparatedbyspaces.
Thisstatementistruewithoutexception.
Theordersofcitationarealphabetical,withtheexceptionofhydrogenamongthecations,whichisalwayscitedlast.
Saltscontainingacid(replaceable)hydrogencontainthehydro-gennameassociateddirectlywithitsanionandwithoutaspaceunlessthehydronisunequivocallyincationicform.
Examples91.
NaHCO3sodiumhydrogencarbonate92.
K2HPO4dipotassiumhydrogenphosphate93.
KMgFmagnesiumpotassiumfluoride(optionallytrifluoride)94.
Na(U02)3[Zn(H20)6](CH3CO2)9hexaaquazincsodiumtriuranylnonaacetate95.
MgNHPO.
6HOammoniummagnesiumphosphate—water(1/6)orammoniummagnesiumphosphatehexahydrate96.
NaClNaF2Na2SO4hexasodiumchloridefluoridebis(sulfate),empiricalformulaNa6C1F(504)297.
Ca5F(PO)3pentacalciumfluoridetris(phosphate)Therecommendedmethodsofnaminghydratesanddoublesaltsshouldbeevidentfromtheseexamples.
Thenamesofgroupsthatcanberegardedassubstituentsinorganiccompoundsorasligandsonmetalsareoftenthesameasthenamesofthecorrespondingradicals.
Namesofradicals(andoftherelatedsubstituentgroups)aregenerallyderivedfromparenthydridenamesbymodifyingtheirnameswiththesuffix-yl,accordingtotherulesofsubstitutivenomenclature.
Sometimescontractionsareused.
48NAMINGOFSUBSTANCESExamples98.
SiH3SiH3silyl99.
SnC13SnC13trichiorostannyl100.
BHBH2boryl101.
CH3CH3methylIninorganicchemistry,certainsubstituentgroupsretaintrivialnamesthatarestillingeneraluse.
Examples102.
OHhydroxyl103.
COcarbonyl104.
SO2sulfonyl105.
Cr02chromylAcompletelistisgiveninTable4.
1.
Thesenamesmaybeusedininorganicfunctionalclassnames.
Examples106.
COC12carbonylchloride107.
NOC1nitrosylchloride108.
SO2NHsulfurylimide109.
102FiodylfluorideElementsubstituentgroupnamesareformedbyaddingthesuffix-iotothestemofthename(compareanionnameformation).
Examples110.
Clchlorio(chloroifinoxidationstate—i)111.
Nasodio112.
C1Hgchloromercurio113.
(OC)4Cotetracarbonylcobaltio114.
F5SpentafluorosulfurioThefulllistofsuchnamesisgiveninTable4.
3.
4.
3MORECOMPLEXNOMENCLATURESYSTEMSWhenitisrequiredtoconveymoreinformationthanisimpliedbyasimplecompo-sitionalname,otherapproachestonameconstructionareadopted.
Thestructureofthecompoundunderconsiderationgenerallydictatesthenameadopted,eventhoughacompoundmaybenamedcorrectlyinmorewaysthanone.
Formolecularcom-pounds,substitutivenomenclature,originallydevelopedfornamingorganiccom-poundsandtheoldestsystematicnomenclaturestillinuse,isgenerallyused.
Thissystem,whichreliesupontheconceptofaparentcompoundfromwhichaseriesofproductsmaybederivedinaformalfashionbyreplacement(or,otherwise,49CHAPTER4Table4.
3Namesofelementsassubstituentgroups.
*ElementnameRadicalnameElementnameRadicalnameActiniumAluminiumAmericiumAntimonyArgonArsenicAstatineBariumBerkeliumBerylliumBismuthBoronBromineCadmiumCaesiumCalciumCaliforniumCarbonCeriumChlorineChromiumCobaltCopper(cuprum)CuriumDeuteriumDysprosiumEinsteiniumErbiumEuropiumFermiumFluorineFranciumGadoliniumGalliumGermaniumGold(aurum)HafniumHeliumHolmiumHydrogenIndiumIodineIridiumIron(ferrum)KryptonLanthanumLawrenciumLead(plumbum)LithiumLutetiumMagnesiumManganeseMendeleviumActinioAluminioAmericioAntimonioArgonioArsenioAstatioBarioBerkelioBeryllioBismuthioBorioBromioCadmioCaesioCalcioCalifornioCerioChlorioChromioCobaltioCuprioCurioDeuterioDysprosioEinsteinioErbioEuropioFermioFluorioFrancioGadolinioGallioGermanioAurioHafnioHelioHolmioIndioIodioIridioFerrioKryptonioLanthanioLawrencioPlumbioLithioLutetioMagnesioManganioMendelevioMercuryMolybdenumNeodymiumNeonNeptuniumNickelNiobiumNitrogenNobeliumOsmiumOxygenPalladiumPhosphorusPlatinumPlutoniumPoloniumPotassiumPraseodymiumPromethiumProtactiniumRadiumRadonRheniumRhodiumRubidiumRutheniumSamariumScandiumSeleniumSiliconSilver(argentum)SodiumStrontiumSulfurTantalumTechnetiumTelluriumTerbiumThalliumThoriumThuliumTin(stannum)TitaniumTritiumTungsten(wolfram)UraniumVanadiumXenonYtterbiumYttriumZincZirconiumMercurioMolybdenioNeodymioNeonioNeptunioNickelioNiobioNobelioOsmioPalladioPhosphorioPlatinioPlutonioPolonioPotassio(kalio)PraseodymioPromethioProtactinioRadioRadonioRhenioRhodioRubidioRuthenioSamarioScandioSelenioSilicioArgentioSodio(natrio)StrontioSulfurioTantalioTechnetioTellurioTerbioThallioThorioThulioStannioTitanioTritioTungstenio(wolframio)UranioVanadioXenonioYtterbioYttrioZincioZirconio50*Thesenamesareusedinorganicsubstitutivenomenclatureforsituationsinwhichthesubstituentgroupisjoinedtotheparentskeletonbyasingleelement—carbonbond.
NAMINGOFSUBSTANCESsubstitution),generallyofahydrogenatombyanotheratomorgroup(substituent),isnoteasilyappliedtocoordinationcompounds,forwhichanadditivesystemhasbeendeveloped.
ThisadditivesystemarosefromtheconceptsofcomplexformationdevisedbyWerneraroundthebeginningofthetwentiethcentury.
Itcanbeusedalsoforcompoundsformallyderivedbyreplacingaskeletalcarbonatomofaparenthydridebyaheteroatomsuchassiliconorevenametalatom.
Thisusagewillbedescribedbelow.
Polymericcompounds(macromolecules)donotfalleasilyintoeitherofthesecategories,andforthemasubsystemofmacromolecularnomenclaturehasbeendeveloped.
AbriefintroductiontomacromolecularnomenclatureispresentedinChapter6.
Non-stoichiometriccompoundsalsoareclearlydifficulttonamewithintheconstraintsofadescriptionwhichgenerallyimplieslocalisedelectron-pairbondsorspecificatom—atominteractions.
Forthese,furthersystemsofnomenclatureareintheprocessofdevelopment.
Finally,oxoacidsandinorganicringsandchainshavetheirownnomenclaturevariants.
Thisisnotanexhaustivelist,butitillustratesthefactthatthechoiceofanappropriatenamingmethodisafunctionofthesubstancetobenamed,andthattheremaybemorethanonewayofderivingacorrectname.
4.
4COORDINATIONNOMENCLATURE,ANADDITIVENOMENCLATURE4.
4.
1IntroductionCoordinationnomenclaturewasdevelopedusingthesameconceptsthatweredevelopedtocategorisecoordinationcompounds.
Itwasrecognisedthat,althoughmetalsexhibitwhatweretermed'primaryvalencies'incompoundssuchasNiCl2,Fe2(SO4)3andPtC12,additioncompoundscouldbeformedinwhich'secondaryvalencies'werealsoexhibited.
ExamplesofsuchcompoundsincludeNiC124H2OandPtC12.
2KC1.
Theexerciseofthissecondaryvalencewasessentiallyrecognisedasanexpressionofmetal—ligandcoordination.
ThisgaverisetotheWernertheoryofcoordinationcompounds,andcoordinationnomenclatureismosteasily,althoughnotexclusively,appliedtocoordinationcompounds.
Coordinationnomenclaturereliesontheidentificationofacoordinationentity:acentralatom(usuallyametal)surroundedbyasetofligands.
Intheoriginalelectronicformulations,thebondingbetweenthemetalatomandtheligandin-volvedthesharingofalonepairofelectronsoftheligand(donor)withthemetal(acceptor).
Clearly,termssuchas'freeligand'and'toligand'areetymologicallyandlogicallyunsound,despitetheiradoptioninsomelessenlightenedcircles.
Typicalformulaeofcoordinationentitiesare[CoC14]2,[Co2(CO)8},[NiCl2(PEt3)2]and[VC13(NCMe)3].
Notetheuseofsquarebracketstodefinetheentity,whetherchargedornot.
Thisusagediffersfromthatinorganicnomenclaturesystems.
Apolymericmaterialisdesignated{MCl}or,ifdesired,[{MCl}],butnever[MCl].
Similarly,theempiricalformulaPtC12(PEt3)correspondstothedinuclearspecies[{PtCl2(PEt3)}2],whichshouldneverbewritten[PtC12(PEt3)]2.
Clearly,therecanbenameduplicationwhencoordinationnomenclatureprinci-plesareappliedtosystemsnotnormallyregardedascoordinationcompounds.
Thus,51CHAPTER4[SiC14(C5H5N)2]isacoordinationcompound.
Formally,onemightrepresentSiC!
4itselfasSi"(orSi4)withfourchlorideligands.
Toinsistonaformulation[SiC!
4]wouldbemerepedantry.
Nevertheless,acoordinationname(seebelow)mightbeappropriateinsomecircumstances.
4.
4.
2DefinitionsAcoordinationentityiscomposedofacentralatomoratomstowhichareattachedotheratomsorgroupsofatoms,whicharetermedligands.
Acentralatomoccupiesacentralpositionwithinthecoordinationentity.
Theligandsattachedtoacentralatomdefineacoordinationpolyhedron.
Eachligandisassumedtobeatthevertexofanappropriatepolyhedron.
TheusualpolyhedraareshowninTable3.
3andtheyarealsolistedinTable4.
4.
Notethattheseareadequatetodescribemostsimplecoordinationcompounds,butthatrealmoleculesdonotalwaysfallintothesesimplecategories.
Inthepresentationofacoordinationpolyhedrongraphically,thelinesdefiningthepolyhedronedgesarenotindicativeofbonds.
2—Cl2—ClCl//tC1/ClClCl—-/\OClThemostcommon'polyhedra'encounteredinsimplecoordinationchemistryarethesquare,thetetrahedronandtheoctahedron.
Atthislevelofapproximation,eachbondbetweenthemetalandaligandisconsideredtobeatwo-electronsigmabond.
Forthepurposesofelectroncounting(asintheinert-gasrule),thisisnormallyadequate.
Thenumberofsuchbondsisthecoordinationnumber.
Eachsingle,simpleligandcontributesunitytothisnumber.
Thus,asquareplanarcoordinationimpliesacoordinationnumberof4.
Anoctahedronimpliesavalueof6.
ThetypicalvaluesarealsoincludedinTable4.
4.
However,manyligandsdonotbehaveasdonorsofasingleelectronpair.
Someligandsdonatetwoormoreelectronpairstothesamecentralatomfromdifferentdonoratoms.
Suchligandsaresaidtobechelatingligands,andtheyformchelaterings,closedbythecentralatom.
Thephenomenonistermedchelation.
ExampleClNH2\1\/CH2I.
I/\,CH2ClNH252Table4.
4Listofpolyhedralsymbols.
*NAMINGOFSUBSTANCESCoordinationpolyhedronCoordinationnumberPolyhedralsymbolLinear2L-2Angular2A-2Trigonalplane3TP-3Trigonalpyramid3TPY-3Tetrahedron4T-4Squareplane4SP-4Squarepyramid4SPY-4Trigonalbipyramid5TBPY-5Squarepyramid5SPY-5Octahedron6OC-6Trigonalprism6TPR-6Pentagonalbipyramid7PBPY-7Octahedron,facemonocapped7OCF-7Trigonalprism,squarefacemonocapped7TPRS-7Cube8CU-8Squareantiprism8SAPR-8Dodecahedron8DD-8Hexagonalbipyramid8HBPY-8Octahedron,trans-bicapped8OCT-8Trigonalprism,triangularfacebicapped8TPRT-8Trigonalprism,squarefacebicapped8TPRS-8Trigonalprism,squarefacetricapped9TPRS-9Heptagonalbipyramid9HBPY-9*Strictly,notallthegeometriescanberepresentedbypolyhedra.
SometimesbondsthatinvolveaneutralliganddonatinganelectronpairarerepresentedbyanarrowasfromH2NCH2CH2NH2above,andbondsthatcanformallyberegardedasinvolvinganelectronfromeachpartnerareshown,asusual,byaline.
Theseformalismsarearbitraryandarenotrecommended.
Thenumberofelectronpairsdonatedbyasingleligandtoaspecificcentralatomistermedthedenticity.
Ligandsthatdonateonepairaremonodentate,thosethatdonatetwoaredidentate,thosethatdonatethreearetridentate,andsoon.
ExampleH/CH2C22+NNH2.
c2\/H2C2/N,CH2NH2NH2tetradentatecoordinationSometimesligandswithtwoormorepotentialdonorsitesbondtotwo(ormore)differentcentralatomsratherthantoone,formingabridgebetweencentralatoms.
Itmaynotbenecessaryfortheligandinsuchasystemtobelikeethane-l,2-diamine,withtwodistinctpotentialdonoratoms.
Adonoratomwithtwoormorepairsofnon-bondingelectronsinitsvalenceshellcanalsodonatethemtodifferentcentral53CHAPTER4atoms.
Suchligands,ofwhatevertype,arecalledbridgingligands.
Theybondtotwoormorecentralatomssimultaneously.
Thenumberofcentralatomsinasinglecoordinationentityisdenotedbythenuclearity:mononuclear,dinuclear,trinuclear,etc.
Atomsthatcanbridgeinclude5,0andCl.
ExamplesClAlAlC1-__C1C1A12C16,adinuclearcomplexwithbridgingchlorideions.
2—MeSFeS/1/1SFeSMe4.
II5——FeSMe//MeSFeS[Fe454(SMe)4]2,atetranuclearcomplexwithbridgingsulfideions.
5.
[(NH3)5CoNH2CH2CH2NH2Co(NH3)5}6Thiscontainsbis(monodentate)bridgingethane-l,2-diamine.
Theoriginalconceptsofmetal—ligandbondingwereessentiallyrelatedtothedativecovalentbond;thedevelopmentoforganometallicchemistryhasrevealedafurtherwayinwhichligandscansupplymorethanoneelectronpairtoacentralatom.
Thisisexemplifiedbytheclassicalcasesofbis(benzene)chromiumandbis(cyclopentadienyl)iron,trivialnameferrocene.
Thesemoleculesarecharacterisedbythebondingofaformallyunsaturatedsystem(intheorganicchemistrysense,butexpandedtoincludearomaticsystems)toacentralatom,usuallyametalatom.
ExamplesC__CH26.
/Pt/CH27.
Fe8.
ClCl()Inthesimplercases,suchasethylene,the7t-electronpaircanbedonatedtothemetaljustlikealonepairon,say,thenitrogenofammonia.
Thisresultsinacontributionofunitytothecoordinationnumber,buttwocarbonatomsareboundtothecentralatom.
Thehapticityoftheethyleneisdefinedastwoandisdenotedformallybythesymboli2.
Ingeneral,thehapticityofaligandisthenumberofligatingatoms,n,intheligandthatbindtothemetal,andisrepresentedbythesymbolT1.
Inthebis(benzene)chromiummolecule,eachdoublebondofeachbenzenemoleculemaybeconsideredasdonatingtwoelectrons.
Thebenzenemoleculesare54NAMINGOFSUBSTANCESthusi6,andthecoordinationnumberofthechromiumisalso6.
Moleculeswithoddnumbersofcarbonatomscanalsobeinvolved,althoughinsuchacaseaformalchargemustbeassignedtothehydrocarbonmolecule.
Thusinbis(cyclopentadi-enyl)iron,eachcyclopentadienylisconsideredtocontributesixelectronstotheiron,i.
e.
itisformallyregardedascyclopentadienide,C5H5.
Eachligandispentahaptoori,buteachsuppliessixelectrons.
Onemightcaretodefinethecoordinationnumberoftheironatominthiscaseas6,buttheconceptisreallylosingsomeofitsclarityinsuchinstances.
Theimportantfactorissixelectrons.
Afurtherpointtonoteisthat,althoughtheorganicligandsarenamedasradicals,theyareformallytreatedasanions.
Thisisgenerallytrueoforganicgroupsincoordinationnomenclature,andincludesmethyl,ethyl,allylandphenyl.
Thisdiscussionimpliesthatthehaptosymbol,i,isnotstrictlyrelatedtoelectronpairs.
Itdefinesthemannerinwhichtheligandbindstothecentralatom.
Thus,eveni'isallowed,althoughintermsofitsoriginalIUPACdefinitionthatrequiredthedonatingatomsoftheligandtobecontiguous,thisisanonsense.
Onefinalconceptneedstobementioned.
Inmanycompounds,twocentralatomscanbebridgedbyadirectbondbetweenthem,withoutanybridgingligand.
Thisbondoccupiesapositioninthecoordinationshellwithoutusingalonepair.
Essentially,thetwocentralatomssharepairsofelectrons,oneelectroncomingfromeachcentralatominmostcases.
Thisisreflectedinthecorrespondingoxidationstates.
Examples9.
[Br4Re-ReBr4]210.
[(CO)5Re-Co(CO)4]Nomenclaturepracticedoesnotdefinethemultiplicityofsuchbonds,betheysingle,double,tripleorevenquadruple.
Itadoptsadevicetoindicatethatabondexistsbetweenthemetalatoms.
Thiswillbepresentedbelow.
4.
4.
3Mononuclearcoordinationcompounds4.
4.
3.
1Formulae.
Thecentralatomislistedfirst.
Theformallyanionicligandsappearnext,listedinalphabeticalorderofthefirstsymbolsoftheirindividualformulae.
Theneutralligandsfollow,alsoinalphabeticalorder.
Polydentateligandsareincludedinalphabeticalorder,theformulatobepresentedasdiscussedinChapter3.
Theformulafortheentirecoordinationentity,whetherchargedornot,isenclosedinsquarebrackets.
Forcoordinationformulae,thenestingorderofenclosingmarksisasgivenonp.
13.
Thechargeonanionisindicatedintheusualwaybyuseofarightsuperscript.
Oxidationstatesofparticularatomsareindicatedbyanappropriateromannumeralasarightsuperscripttothesymboloftheatominquestion,andnotinparenthesesontheline.
Intheformulaofasaltcontainingcoordinationentities,cationalwaysprecedesanion,nochargesareindicatedandthereisnospacebetweentheformulaeforcationandanion.
Examples1.
[Co(NH3)6]Cl2.
[PtC14]255CHAPTER43.
[CoC1(NH3)5]C16.
[Cr"(NCS)4(NH3)2]4.
Na[PtBrC1(N02)(NH3)J7.
[Fe"(CO)4]25.
[CaC12{OC(NH2)2}2]Thepreciseformofaformulashouldbedictatedbytheneedsoftheuser.
Forexample,itisgenerallyrecommendedthataligandformulawithinacoordinationformulabewrittensothatthedonoratomcomesfirst,e.
g.
[TiCl3(NCMe)3],butthisisnotmandatoryandshouldnotaffecttherecommendedorderofligandcitation.
Itmayalsobeimpossibletoputallthedonoratomsfirst,e.
g.
wheretwodonorsarepresentinachelatecomplex:[Co(NH2CH2CH2NH2)3]3.
Whethertheethane-l,2-diamineisdisplayedasshown,orsimplyaggregatedas[Co(C2H8N2)3]3tisamatterofchoice.
Certainlythereisaconflictbetweenthislastformandthesuggestionthatthedonoratomsbewrittenfirst.
Theaimshouldalwaysbeclarity,attheexpenseofrigidadherencetorecommendations.
Itisofteninconvenienttorepresentalltheligandformulaeindetail.
Abbrevia-tionsareoftenusedandareindeedencouraged,withcertainprovisos.
Theseare:theabbreviationsshouldallbewritteninlowercase(withminorexceptions,suchasMe,EtandPh)andpreferablynotmorethanfourletters;withcertainexceptionsofwidecurrency,abbreviationsshouldbedefinedinatextwhentheyfirstappear;inaformula,theabbreviationshouldbeenclosedinparentheses,anditsplaceinthecitationsequenceshouldbedeterminedbyitsformula,asdiscussedabove;andparticularattentionshouldbepaidtothelossofhydronsfromaligandprecursor.
Thislastprovisoisexemplifiedasfollows.
EthylenediaminetetraaceticacidshouldberenderedH4edta.
Theionsderivedfromit,whichareoftenligandsincoordinationentities,arethen(H3edta),(H2edta)2,(Hedta)3and(edta)4.
Thisavoidsmonstrositiessuchasedta-H2andedtaH_2whichariseiftheparentacidisrepresentedasedta.
AlistofrecommendedabbreviationsispresentedinTable4.
5.
4.
4.
3.
2Names.
Theadditionofligandstoacentralatomisparalleledinnameconstruction.
Thenamesoftheligandsareaddedtothatofthecentralatom.
Theligandsarelistedinalphabeticalorderregardlessofligandtype.
Numericalprefixesareignoredinthisorderingprocedure,unlesstheyarepartoftheligandname.
Chargenumberandoxidationnumberareusedasnecessaryintheusualway.
Ofthetwokindsofnumericalprefix(seeTable4.
2),thesimpledi-,tn-,tetra-,etc.
aregenerallyrecommended.
Theprefixesbis-,tris-,tetrakis-,etc.
aretobeusedonlywithmorecomplexexpressionsandtoavoidambiguity.
Theynormallyrequireparenthesesaroundthenametheyqualify.
Thenestingorderofenclosingmarksisascitedonp.
13.
Thereisnormallynoelisionininstancessuchastetraammineandthetwoadjacentletters'a'arepronouncedseparately.
ThenamesofligandsrecommendedforgeneralpurposesaregiveninTable4.
6.
Thenamesforanionicligandsendin-o.
Iftheanionnameendsin-ite,-ateor-ide,theligandnameischangedto-ito,-atoor-ido.
Thehalogenidonamesare,bycustom,abbreviatedtohalo.
Notethathydrogenasaligandisalwaysregardedasanionic,withthenamehydride.
Thenamesofneutralandcationicligandsarenevermodified.
Waterandammoniamoleculesasligandstakethenamesaquaandammine,respectively.
Parenthesesarealwaysplacedaroundligandnames,whichthemselvescontainmultiplicativeprefixes,andarealsousedtoensureclarity,but56Table4.
5Representationofligandnamesbyabbreviation.
*NAMINGOFSUBSTANCESAbbreviationCommonnameSystematicnameDiketonesHacacacetylacetone2,4-pentanedioneHhfahexafluoroacetylacetone1,1,l,5,5,5-hexafiuoropentane-2,4-dioneHbabenzoylacetonel-phenylbutane-l,3-dioneHfodl,l,l,2,2,3,3-heptafluoro-7,7-dimethyl-4,6-6,6,7,7,8,8,8-heptafluoro-2,2-dimethyloctanedioneoctane-3,5-dioneHftatrifluoroacetylacetonel,l,l-trifluoropentane-2,4-dioneHdbmdibenzoylmethanel,3-diphenylpropane-l,3-dioneHdpmdipivaloylmethane2,2,6,6-tetramethylheptane-3,5-dioneAminoakoholsHeaethanolamine2-aminoethanolH3teatriethanolamine2,2',2''-nitrilotriethanolH2deadiethanolamine2,2'-iminodiethanolHydrocarbonscodcyclooctadienecycloocta-l,5-dienecotcyclooctatetraenecycloocta-l,3,5,7-tetraeneCpcyclopentadienylcyclopentadienylCycyclohexylcyclohexylAcacetylacetylBubutylbutylBzlbenzylbenzylEtethylethylMemethylmethylnbdnorbornadienebicyclo[2.
2.
l]hepta-2,5-dienePhphenylphenylPrpropylpropylHeterocyclespypyridinepyridinethftetrahydrofurantetrahydrofuranHpzpyrazolelH-pyrazoleHimimidazole1H-imidazoleterpy2,2',2''-terpyridine2,2':6',2''-terpyridinepicolinea-picoline2-methylpyridineHbpz4hydrogentetra(l-pyrazolyl)borate(l—)hydrogentetrakis(1H-pyrazolato-N)borate(l—)isnisonicotinamide4-pyridinecarboxamidenianicotinamide3-pyridinecarboxamidepippiperidinepiperidinelutlutidine2,6-dimethylpyridineHbimbenzimidazolelH-benzimidazoleChelatingandotherligandsH4edtaethylenediaminetetraaceticacid(ethane-1,2-diyldinitrilo)tetraaceticacidH5dtpaN,N,N',N'',N''-diethylenetriaminepentaaceticaciddiylnitrilo)]tetraaceticacidH3ntanitrilotriaceticacidH4cdta_cyclohexanediaminetetraaceticacidtrans-(cyclohexane-l,2-diyldinitrilo)tetraaceticacidH2idaiminodiaceticacidiminodiaceticaciddiendiethylenetriamineN-(2-aminoethyl)ethane-l,2-diamineenethylenediamineethane-1,2-diaminepnpropylenediaminepropane-l,2-diaminetmenN,N,N',N'-tetramethyietnylenediamineN,N,N',N'-tetramethylethane-l,2-diaminetntrimethylenediaminepropane-1,3-diamineContinuedonp.
58.
57CHAPTER4Table4.
5(Continued.
)AbbreviationCommonnameSystematicnametris(2-aminoethyl)aminetriethylenetetramine1,2-diaminocyclohexanehexamethylenetetraminethiosemicarbazide1,2-bis(diethylphosphino)ethaneo-phenylenebis(dimethylarsine)1,2-bis(diphenylphosphino)ethane2,3-O-isopropylidene-2,3-dihydroxy-1,4-triethylenediamine1,4,8,11-tetraazaundecane1,5,9,13-tetraazatridecaneureadmfdimethylformamideSchiffbaseH2salenbis(salicylidene)ethylenediamine1,4,7,10,13,16-hexaoxacyclooctadecane2,3-benzo-1,4,7,10,13-pentaoxacyclopentadec-2-ene4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.
8.
8]hexacosanecryptand2114,7,13,18-tetraoxa-1,10-diazabicyclo[8.
5.
5]icosane1,4,7,10-tetrathiacyclododecanephthalocyaninetetraphenylporphyrinoctaethylporphyrinprotoporphyrinIXN,N-bis(2-aminoethyl)ethane-1,2-diamineN,N'-bis(2-aminoethyl)ethane-1,2-diaminecyclohexane-1,2-diamine1,3,5,7-tetraazatricyclo[3.
3.
1.
13'7]decanehydrazinecarbothioamideethane-1,2-diylbis(diethylphosphine)1,2-phenylenebis(dimethylarsine)ethane-1,2-diylbis(diphenylphosphine)3,4-bis[(diphenylphosphinyl)methyl]-2,2-dimethyl-1,3-dioxolane[2-[(diphenylphosphino)methyl]-2-methylpropane-1,3-diyl]bis(diphenylphosphine)2,2'-bipyridine-2,3-butanedionedioximesulfinyldimethane1,10-phenanthrolinethioureaimidodicarbonimidicdiamide2,3-dimercaptobut-2-enedinitrileethenetetracarbonitrile2,2'-(cyclohexa-2,5-diene-1,4-diylidene)bis(1,3-propanedinitrile)1,4-diazabicyclo[2.
2.
2]octaneN,N'-bis(2-aminoethyl)propane-1,3-diamineN,N'-bis(3-aminopropyl)propane-1,3-diamineureaN,N-dimethylformamide2,2'-[ethane-l,2-diylbis(nitrilo-methylidyne)]diphenol4,4'-(ethane-1,2-diyldinitrilo)bis(pentan-2-one)N-[(2-hydroxyphenyl)methylene]glycine2,2'-[propane-1,3-diylbis(nitrilo-methylidyne)]diphenol2,2'-[iminobis(ethane-1,2-diylnitrilo-methylidyne)]diphenol2,2'-[ethane-l,2-diylbis(nitrilo-methylidyne)]dibenzenethiol1,4,7,10,13,16-hexaoxacyclooctadecane2,3,5,6,8,9,11,12-octahydro-1,4,7,10,13-benzopentaoxacyclopentadecine4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.
8.
8]hexacosane4,7,13,18-tetraoxa-1,10-diazabicyclo[8.
5.
5]icosane1,4,7,10-tetrathiacyclododecanephthalocyanine5,10,15,20-tetraphenylporphyrin2,3,7,8,12,13,17,18-octaethylporphyrin3,7,12,17-tetramethyl-8,13-divinylporphyrin-2,18-dipropanoicacidtrentrienchxnhmtaHthscdepediarsdppedioptriphoshmpabpyH2dmgdmsophentuHbigHEt2dtcH2mnttcnetcnqdabco2,3,2-tet3,3,3-teturhexamethyiphosphorictriamide2,2'-bipyridinedimethyiglyoximedimethylsulfoxide1,10-phenanthrolinethioureabiguanidediethyldithiocarbamicacidmaleonitriledithioltetracyanoethylenetetracyanoquinodimethansalicylideneglycinebis(salicylidene)-1,3-diaminopropanebis(salicylidene)diethylenetriaminebis(2-mercaptobenzylidene)ethylenediamineH2acacenH2salglyH2saltnH2saldienH2tsalenMacrocycles18-crown-6benzo-15-crown-Scryptand222[12]aneS4H2pcH2tppH2oepppIX58Continued.
Table4.
5(Continued.
)NAMINGOFSUBSTANCESAbbreviationCommonnameSystematicname[l8JaneP4O21,1O-dioxa-4,7,13,16-1,1O-dioxa-4,7,13,16-[14]aneN4[14]1,3-dieneN4tetraphosphacyclooctadecane1,4,8,11-tetraazacyclotetradecane1,4,8,11-tetraazacyclotetradeca-1,3-dienetetraphosphacyclooctadecane1,4,8,11-tetraazacyclotetradecane1,4,8,11-tetraazacyclotetradeca-1,3-dieneMe4[14]-aneN4cyclam2,3,9,1O-tetramethyl-1,4,8,11-tetraazacyclotetradecane2,3,9,1O-tetramethyl-1,4,8,11-tetraazacyclotetradecane1,4,8,11-tetraazacyclotetradecane*Thefollowingpracticesshouldbefollowedintheuseofabbreviations.
Itshouldbeassumedthatthereaderwillnotbefamiliarwiththeabbreviations.
Consequently,alltextshouldexplaintheabbreviationsituses.
Theabbreviationsinthistablearewidelyused,anditishopedthattheywillbecomestandard.
Thecommonlyacceptedabbreviationsfororganicgroups(Me,methyl;Et,ethyl;Ph,phenyl;etc.
)shouldnotbeusedwithanyothermeanings.
Themostusefulabbreviationsarethosethatreadilysuggesttheligandinquestion,eitherbecausetheyareobviouslyderivedfromtheligandnameorbecausetheyaresystematicallyrelatedtostructure.
ThesequentialpositionsofligandabbreviationsinformulaeshouldbeinaccordancewithSection4.
4.
3.
1.
Lowercaselettersareusedforallabbreviations,exceptforthoseofcertainhydrocarbonradicals.
Informulae,theligandabbreviationshouldbeinparentheses,asin[Co(en)3]3tThosehydrogenatomsthatcanbereplacedbythemetalatomareshownintheabbreviationbythesymbolH.
Thus,themoleculeHacacformsananionicligandthatisabbreviatedacac.
3.
[Co(NH3)6]C134.
[CoCl(NH3)5}Cl25.
[CoC1(N02)(NH3)4]Cl6.
[PtCl(NH2CH3)(NH3)2]Cl7.
[CuC12{OC(NH2)2}2]8.
K2[PdC14]9.
K[OsCl5N]10.
Na[PtBrC1(N02)(NH3)]11.
[Fe(CNCH3)6]Br212.
[Ru(HSO3)2(NH3)4]13.
[Co(H20)2(NH3)4]C1314.
[PtC12(C5H5N)(NH3)]15.
Ba[BrF4]216.
K[CrF4O]17.
[Ni(H20)2(NH3)4]S04potassiumhexacyanoferrate(ii)potassiumhexacyanoferrate(4—)tetrapotassiumhexacyanoferratehexaamminecobalt(iii)chloridepentaamminechlorocobalt(2+)chloridetetraamminechloronitrito-N-cobalt(iii)chloridediamminechloro(methylamine)platinum(ii)chloridedichlorobis(urea)copper(ii)potassiumtetrachloropalladate(ii)potassiumpentachloronitridoosmate(2—)sodiumamminebromochloronitrito-N-platinate(1—)hexakis(methylisocyanide)iron(ii)bromidetetraamminebis(hydrogensulfito)ruthenium(ii)tetraamminediaquacobalt(iii)chlorideamminedichloro(pyridine)platinum(ii)bariumtetrafluorobromate(iii)potassiumtetrafiuorooxochromate(v)tetraamminediaquanickel(ii)sulfate59aqua,ammine,carbonyl(CO)andnitrosyl(NO)donotrequirethem.
Thenamesofallcationicandneutralentitiesendinthenameoftheelement,togetherwiththecharge(ifappropriate)ortheoxidationstate(ifdesired).
Thenamesofcomplexanionsrequiremodification,andthisisachievedbyaddingthetermination-ate.
Alltheserecommendationsareillustratedinthefollowingexam-ples.
Examples1.
Dichloro(diphenylphosphine)(thiourea)platinum(ii)2.
K4[Fe(CN)6]CHAPTER4Table4.
6Namesofligands.
*FormulaSystematicnameAlternativeligandnameLigandsbasedonGroup15elementsN2(dinitrogen)P4(tetraphosphorus)As4(tetraarsenic)N3nitridoP3phosphidoAs3arsenido(N2)2[dinitndo(2—)](N2)4[dinitrido(4—)][hydrazido(4—)}(N3)(tnnitrido)azidot(P2)2[diphosphido(2—)](CN)cyano(NCO)(cyanato)(NCS)(thiocyanato)(NCSe)(selenocyanato)(NCN)2[carbodiimidato(2—).
]NF3(tnfluoroazane)(nitrogentnfluonde)NH3(azane)amminet$PH3(phosphane)(phosphine)AsH3(arsane)(arsine)SbH3(stibane)(stibine)(NH)2azanediidoimidot,1(NH2)azanidoamidot4(PH)2phosphanediidophosphinidene(PH2)phosphanidophosphino(SbH)2stibanediidostibylene(SbH2)stibanidostibinoj(AsH)2arsanediidoarsinidenej(A5H2)arsanidoarsinoj()2_(fluoroazanediido)(fluonmido)(C1HN)(chloroazanido)(chloramido)(C12N)(dichioroazanido)(dichioramido)(FP)2(fluorophosphanediido)(F2P)(difluorophosphanido)(difluorophosphido)(phosphonousdifluoridato)tCH3NH2(methanamine)(methy1amine)(CH3)2NH(N-methylmethanamine)(dimethylamine)(CH3)3N(N,N-dimethylmethanamine)(tnmethylamine)CH3PH2(methyiphosphane)(methyiphosphine)(CH3)2PH(dimethyiphosphane)(dimethyiphosphine)(CH3)3P(tnmethylphosphane)(trimethyiphosphine)(CH3N)2[methanaminato(2—)](methylimido)(CH3NH)[methanaminato(l.
-)](methylamido)[(CH3)2N](N-methylmethanaminato)(dimethylamido)[(CH3)2P](dimethyiphosphanido)(dimethyiphosphino)(CH3P)2(methylphosphanediido)(methylphosphinidene)(CH3PH)(methyiphosphanido)(methyiphosphino)HN=NH(diazene)(diimide),(diimine)H2NNH2(diazane)(hydrazine)HN3(hydrogentrinitride)(hydrogenazide)t(HN=N)(diazenido)(diiminido)(HNN)3(diazanetriido)[hydrazido(3—)](H2NN)2(diazane-l,l-diido)[hydrazido(2—)-N,N](HN—NH)2(diazane-1,2-diido)[hydrazido(2—)-N,N'](H2N—NH)(diazanido)(hydrazido)HP=PH(diphosphene)H2P—PH2(diphosphane)60Continued.
Table4.
6(Continued.
)NAMINGOFSUBSTANCESFormulaSystematicnameAlternativeligandname(HP=P)(diphosphenido)(H2P—P)2(diphosphane-l,l-diido)(HP—PH)2(diphosphane-1,2-diido)(H2PPH)(diphosphanido)HAs=AsH(diarsene)H2AsAsH2(diarsane)(HAsAs)3(diarsanetnido)(H2AsAs)2(diarsane-l,l-diido)(CH3AsH)(methylarsanido)(methylarsino)j(CH3As)2(methylarsanediido)(methylarsinidene)jH2NOH(hydroxyazane)(hydroxylamine)(HNOH)(hydroxylaminato-icN)(hydroxylamido)(H2NO)(hydroxylaminato-icO)(hydroxylamido)(HNO)2[hydroxylaminato(2—)](hydroxylimido)(P03)3-[trioxophosphato(3—)][phosphito(3—)](HPO2)2[hydridodioxophosphato(2—)}[phosphonito(2—)](H2PO)[dihydndooxophosphato(l—)}(phosphonito)(As03)3[trioxoarsenato(3—)]farsenito(3—)](HAsO2)2[hydridodioxoarsenato(2—)}[arsenito(2—)](H2AsO)[dihydridooxoarsenato(l—)](arsinito)(P04)3[tetraoxophosphato(3—)][phosphato(3—)](HPO3)2[hydridotrioxophosphato(2—)][phosphonato(2—)}(H2P02)[dihydndodioxophosphato(l—)(phosphinato)(As04)3[tetraoxoarsenato(3—)][arsenato(3—)](HAsO3)2[hydridotrioxoarsenato(2—)}[arsonato(2—)}(H2AsO2)[dihydridodioxoarsenato(l—)]arsinato(P207)4[js-oxo-hexaoxodiphosphato(4—)][diphosphato(4—)](C6H5N2)(phenyldiazenido)(phenylazo)(N02)[dioxonitrato(l—)]nitnto-O[dioxonitrato(l—)}nitrito-N,nitro(N03)[trioxonitrato(l—)]nitratoNO(nitrogenmonoxide)nitrosylNS(nitrogenmonosulfide)(thionitrosyl)N20(dinitrogenoxide)(N202)2[dioxodinitrato(N—N)(2—)]hyponitritoLigandsbasedonchakogenelements(elementsofGroup16)02(dioxygen)oxygen(octasulfur)02_oxidooxot4S2sulfidothiot,thioxoSe2selenidoselenoxoTe2telluridotelluroxoj(O2)2_[dioxido(2—)]peroxot,peroxyj(02)[dioxido(l—)]hyperoxot,superoxidot4(03)[trioxido(l—)}ozonidot(52)2[disulfido(2—)](dithio)j(55)2[pentasulfido(2—)](pentasulfane-l,5-diido)(Se2)2[diselenido(2—)](diseleno)j(Te2)2[ditellurido(2—)](ditelluro4H20aqua4H2S(sulfane)(hydrogensulfide)tH2Se(selane)(hydrogenselenide)tH2Te(tellane)(hydrogentelluride)t(OH)-hydroxidohydroxot,hydroxyj(SH)sulfanido,(hydrogensulfido)(SeH)selanido,(hydrogenselenido)selenyl(TeH)tellanido,(hydrogentellurido)tellurylContinuedonp.
62.
61CHAPTER4Table4.
6(Continued.
)FormulaSystematicnameAlternativeligandnameH202H252H25e2H255(H02)(H52)(disulfanido)(H55)(pentasulfanido)(CH3O)(methanolato)(C2H50)(ethanolato)(C3H70)(1-propanolato)(C4H90)(1-butanolato)(C5H1O)(1-pentanolato)(C12H250)(1-dodecanolato)(CH3S)(methanethiolato)(C2H55)(ethanethiolato)(C2H4C1O)(2-chioroethanolato)(C6H50)(phenolato)(C6H5S)(benzenethiolato)[C6H4(N02)O](4-nitrophenolato)CO(carbonmonoxide)CS(carbonmonosulfide)(C204)2(ethanedioato)(HCO2)(methanoato)(CH3CO2)(ethanoato)(CH3CH2CO2)(propanoato)(502)2_[dioxosulfato(2—)](503)2_[tnoxosulfato(2—)](HSOJ[hydrogentnoxosulfato(l—)](Se02)2[dioxoselenato(2—)](S202)2_[dioxothiosulfato(2—)](5203)2_ftrioxothiosulfato(2—)](504)2_[tetraoxosulfato(2—)](5206)2_[hexaoxodisulfato(S—S)(2—)](5207)2_[t-oxo-hexaoxodisulfato(2--)](TeO6)6[hexaoxotellurato(6—)]Ligandsbasedonhalogenelements(elementsofGroup17)Br2(dibromine)C1('3)—[C1F2]—[1F4][1F6](ClO)(Cl02)(C103)(C1O4)(IO5)(IO6)ITft\4—k2'-'91[difluorochlorato(l—)][tetrafluoroiodato(l—)][hexafluoroiodato(l—)][oxochlorato(l—)][dioxochlorato(l—)][trioxochlorato(l—)[tetraoxochlorato(l—)][pentaoxoiodato(3—)][hexaoxoiodato(5—)][t-oxo-octaoxodiiodato(4—)](hydrogenperoxide)(hydrogendisulfide)(hydrogendiselenide)(hydrogenpentasulfide)(hydrogenperoxo)t,(hydroperoxy)(hydrogendisulfido),(hydrodisulfido4(hydrogenpentasulfido)methoxot,methoxyethoxot,ethoxyfpropoxidot,propoxyfbutoxidot,butoxy(pentyloxido)t,pentoxy(dodecyloxido)t,(dodecyloxy)(methylthio)phenoxidot,phenoxyf(phenylthio)carbonylt4(thiocarbonyl)t,(carbonothioyl)(oxalato)(formato)(acetato)(propionato)[sulfoxylato(2—)][sulfito(2—)](hydrogensulfito)[selenoxylato(2—)][thiosulfito(2—)][thiosulfato(2—)][sulfato(2—)][dithionato(2—)}[disulfato(2—)]orthotelluratofluorochloro[triiodo(l—)]hypochloritochloritochloratoperchlorato(disulfane)(diselane)(pentasulfane)62*Theuseofenclosingmarkshereistosomeextentarbitrary.
Forexample:[1F4]isregardedasacoordinationcomplex,andhencethesquarebrackets;(Cl03)isregardedasasimpleanion(Section4.
4.
3.
1),andhencetheparentheses.
Thebracessurroundingsystematicnamesoftheligandsarenecessarywhentheyarecombinedintothenameofacoordinationentity.
Fororganicanions,thesequenceofenclosingmarksisinaccordancewithnormalorganicpractice,whichdiffersfromthesequenceusedincoordinationnomenclature.
Enclosingmarksareplacedonligandnamesastheyaretobeusedinnamesofcoordinationentities.
tIUPAC-approvednames.
tNamesusedinthe9thCollectiveIndexofChemicalAbstracts.
§IUPACalternativenamesnormallypreferredinorganicnomenclature.
NAMINGOFSUBSTANCES4.
4.
3.
3Designationofdonoratom.
Insomecases,itmaynotbeevidentwhichatominaligandisthedonor.
ThisisexemplifiedbythenitritoligandinExamples5and10,p.
59.
Thiscanconceivablybindthroughan0orNatom.
Insimplecases,thedonoratomcanbeindicatedbyitalicisedelementsymbolsplacedafterthespecificligandnameandseparatedfromitbyahyphen,asdemonstratedinthoseparticularexamples.
Morecomplexexampleswillbedealtwithbelow.
Withpolydentateligands,thisdevicemaystillbeserviceable.
Thus,dithiooxalateionmaybeattachedthroughSor0,andformulationssuchasdithiooxalato-S,S'anddithiooxalato-0,0'shouldsuffice.
Itcouldbenecessarytousesuperscriptstothedonoratomsymbolsiftheseneedtobedistinguishedbecausethereismorethanoneatomofthesamekindtochoosefrom.
Examples(CH3COCHCOCH3Ypentane-2,4-dionate-C3O=CO%o=c—0-o=C—oIMIIHCOHCOHCOH1.
I2.
IM3.
IMHCOHHCOHCOH/o=—oo=c—o-o=c—otartrato(3—)-0',02tartrato(4—)-02,0tartrato(2—)-01,0Complicatedexamplesaremoreeasilydealtwithusingthekappaconvention,andthisisparticularlyusefulwhereadonoratomispartofagroupthatdoesnotcarryalocantaccordingtoorganicrules.
Thetwooxygenatomsinacarboxylatogroupdemonstratethis.
Thedesignatoriisalocantplacedafterthatportionoftheligandnamethatdenotestheparticularfunctioninwhichtheligatingatomisfound.
Theligatingatomsarerepresentedbysuperscriptnumerals,lettersorprimesaffixedtothedonorelementsymbols,whichfollowiwithoutaspace.
Arightsuperscripttoidenotesthenumberofidenticallyboundligatingatoms.
Examples4H\/:iiNi/\Ph3PPPh2[2-(diphenylphosphino-1P)phenyl-KC']hydrido(triphenylphosphine-lCP)-nickel(II)CH2—CH2+H2NNNHCH2CH2Cl[N,N'-bis(2-amino-iN-ethyl)ethane-1,2-diamine-iN]chloroplatinum(ii)63CHAPTER4CH2—CH2H2NNHNS—'-'CH2PtIci"NNH-2c2Jtj1,N7diammine[2'-deoxyguanylyl-icN7-(3''.
5')-2'-deoxycytidylyl(3'—'.
5')-2'-deoxyguanosinato(2—)-icN7}platinum(ii)+[N-(-amino-icN-ethyl)-N'-(2-aminoethyl)-ethane-1,2-diamine-K2N,N']chloroplatinum(ii)6.
I\LThetwopossibledidentatemodesofbindingofl,4,7-tnazacyclononaneareshowninthenextexamples.
Examples6M'8.
N2isoptional.
Otherwise,thenormalrulesexpoundedformononuclearcomplexesapply.
Examples1.
[Rh3H3{P(OCH3)3}6]trihydridohexakis(trimethylphosphite)trirhodium2.
[CoCu2Sn(CH3){p.
-(C2H302)}2(C5H5)]bis(p.
-acetato)(cyclopentadienyl)(methyl)-cobaltdicoppertin3.
[Fe2Mo2S4(C6H5S)4]2tetrakis(benzenethiolato)tetra-thio(diirondimolybdenum)ate(2—)Ifstructuralinformationisavailable,itcanbeconveyedusingthedevicesalreadydiscussed.
Bridgingligandsarecitedasabove,unlessthesymmetryofthesystemallowsasimplificationusingmultiplicativeprefixes.
Bondingbetweenmetalatomsmaybeindicatedinnamesbyitalicisedelementsymbolsoftheappropriatemetalatoms,separatedbyalongdash,andenclosedinparenthesesafterthelistofcentralatomsandbeforetheioniccharge.
Examples4.
[{Cr(NH3)5}2(p.
-OH)]C15p.
-hydroxo-bis(pentaamminechromium)(5+)pentachloride5.
[PtCl{P(C6H5)3}]2(p.
-Cl)2]di-p.
-chloro-bis[chloro(triphenylphosphine)platinum]6.
[{Fe(NO)2}2{p.
-P(C6H5)2}2]bis(p.
-diphenylphosphido)bis(dinitrosyliron)7.
[Br4ReReBr4]2bis(tetrabromorhenate)(Re—Re)(2—)8.
[Mn2(CO)10Jbis(pentacarbonylmanganese)(Mn—Mn),ordecacarbonyldimanganese(Mn—Mn)Wheretheentitiestoberepresentedarenotsymmetricalbecause,forexample,theycontainatomsofdifferentmetals,anorderofcitationofmetalsmustbeestablished.
Inaformula,thepriorityisestablishedbyuseofTableIVoftheNomenclatureofInorganicChemistry(Table3.
1ofthisbook),thehighestprioritybeingassignedtotheelementreachedlastfollowingthedirectionofthearrow.
Inthename,alphabeticalorderestablishesthepriority.
66Table4.
7Structuraldescriptors.
NAMINGOFSUBSTANCESCoordinationnumberofcentralatomDescriptorPointgroupStructuraldescriptor3trianguloD3h4quadroD4h4tetrahedroTd[Td-(l3)-t4-closo]5D3h[D3h-(l3l)-.
A6-closo]6octahedro°h[Oh-(141)-Ei8-closo]6tnpnsmoD3h8antiprismoS68dodecahedroD2d[D2-(2222)-L6-cloSO]8hexahedro(cube)°h12icosahedro4['h('55l)-E20-closo]Examples129.
[(CO)5Re—Co(CO)4]nonacarbonyl-li5C,2K4C-cobaltrhenium(Co—Re)1210.
carbonyl-1KC-trichloro-11c2C1,2KC1-bis(tnphenylphosphine-licP)iridiummercury(Hg—Ir)11.
[Cr(NH3)5(i.
t-OH)Cr(NH3)4(NH2CH3)]Cl5nonaammine-t-hydroxo(methanamine)dichromium(5+)pentachioride12.
[{Co(NH3)3}2(p.
t-OH)2(i-NO2)]Br3di-p-hydroxo-J.
L-nitrito-icN:KO-bis(triamminecobalt)(3+)tribromide13.
[{Cu(C5H5N)}2(j.
t-C2H302)4]tetrakis(t-acetato-1cO:KO')bis[(pyridine)copper(LI)]Forlargeraggregations,asetofstructuraldescriptors(seeTable4.
7)isused.
Homonuclearentitiescanhaverelativelysimplenamesusingthesedescriptors.
Theexamplesbelowgiveanindicationofhownamesarearrivedat.
Formorecomplexcases,thereaderisreferredtotheNomenclatureofInorganicChemistry,p.
192.
Allthedevicesalreadydiscussedabovecanbecalledintouseasnecessary.
Examples14.
[{Co(CO)3}3(i3-CI)]nonacarbonyl-(ji3-iodomethylidyne)-triangulo-tricobalt(3Co—Co)15.
Cs3[Re3Cl12]caesiumdodecachloro-triangulo-trirhenate(3Re—Re)(3-.
)16.
[Cu4I4{P(C2H5)3}4]tetra-i3-iodo-tetrakis(triethylphosphine)-tetrahedro-tetracopper,ortetra-jt3-iodo-tetrakis(triethylphosphine)[T-(13)-A'-closo]tetracopper67CHAPTER417.
18.
[{Hg(CH3)}4(ji4-S)}2Ph3PPPh3\/Pto/3\0III/\IIIOC/\CO19.
C%%I/2_____oc__1coIIIIIIo020.
[Mo6S8]2IPtMe/1/21Me3PtIMe3Pt——I1//IPtMe322.
[Be4(j.
t-C2H302)6(p.
t4-O)]penta-L-carbony1-1:2K2C;1:4ic2C;2:3K2C;2:4K2C;3:4K2C-heptacarbonyl-11c3C,2KC,31c2C,41cC-tetrahedro-tetracobalt(4Co—Go),orpenta-t-carbonyl-1:2w2C;1:4ic2C;2:3K2C;2:4ic2C;3:4K2C-heptacarbonyl-1K3C,2KC,3K2C,4KC-[Td-(13)4closo]tetracobalt(4Co—Go)t4-thio-tetrakis(methylmercury)(2+)ion,ortetramethyl-1KC,2KC,3KC,4KC-J.
t4-thio-tetrahedro-tetramercury(2+)ion,ortetramethyl-1KC,2KC,3icC,4KC-x4-thio-[Td-(13)-4-closo]tetramercury(2+)ionoctacarbonyl-1K4C,2K4G-bis-(triphenylphosphine-3icP)-triangulo-diironplatinum(Fe—Fe)(2Fe—Pt)octa-jt3-thio-octahedro-hexamolybdate(2—),orocta-t.
t3-thio-[Oh-(l41)-8-closo]hexamo1ybdate(2—)tetra-t3-iodo-tetrakis[trimethylplatinum(Iv)],ortetra-jt3-iodo-dodecamethyl-1K3C,21c3C,31c3C,41(3C-tetrahedro--tetraplatinum(iv),ortetra-ix3-iodo-dodecamethyl-1K3C,2K3C,3ic3G,4K3C-[Td-(l3)-4-closo]tetrap1atinum(iv)hexakis(J-acetato-KO:KO')-L4-oxo-tetrahedro-tetraberyllium,orhexakis(I-acetato-KO:KO')-J.
L4-oxo-[Td-(13)-t4-closo]tetrabery11ium68Thedescriptors[Td-(l3)-Et4-closo]and[Oh-(141)-E8-closo}areusefulforprecisedesignations,butsimplernamesarealsoavailable(seetheNomenclatureofInor-ganicChemistry,p.
192).
4.
4.
5NAMINGOFSUBSTANCESCoordinationnomenclatureforoxoacids,oxoanionsandrelatedcompoundsAnoxoacidisacompoundthatcontainsoxygenandatleastonehydrogenatomattachedtooxygenandproducesaconjugatebasebylossofoneormorehydrons.
Thereisalargeaccumulationoftrivialnamesforsuchcompoundsandtheirderivedanions,andtheseareoftenincomprehensiblewithoutagreatdealofrotelearning.
Inaddition,theconventionalnomenclaturesoftenusesuffixessuchas-ousand-icandprefixessuchashypo-andmeta-thatchangeindetailedmeaningfromelementtoelement.
Forthisreason,suchnomenclaturesarenowstronglydiscouraged.
Coordinationnomenclaturehasbeenadaptedtoprovidesystematicnamesformanyofthesespecies,andseveralsuchnameshavealreadybeenquotedinthistext.
Foramoredetailedtreatment,thereaderisreferredtotheNomenclatureofInorganicChemistry,Chapter9.
Thebasicstrategyistotreattheacidoranionasacoordinationcompound,withthecentralatomoratomsbeingdefinedasthecoordinationcentres,whetherornottheyaremetalatoms.
Theoxygenatomsarethendefinedastheligands.
Thequestionofwhetherthe'acid'hydrogenatomsareionisedhydronsormoreproperlyregardedaspartofacoordinatedhydroxideionisavoidedbycitingsuchhydrogenatomsfirstinthename,unlessthereisgoodempiricalreasonfornotdoingso.
Inthenameslistedbelow,thesystematicnamesoftheanionsareobtainedsimplybyomittingtheinitial'acid'hydrogens.
Examples1.
H3B032.
H2C033.
HNO34.
HNO5.
HPHO6.
H3P037.
H2PHO8.
H3P049.
HP2O-,10.
(HPO,11.
(HO)2OPPO(OH)212.
H2S0413.
H2S20714.
H2520315.
H2S20616.
H2S20417.
H2S03trihydrogentrioxoboratedihydrogentrioxocarbonatehydrogentrioxonitratehydrogendioxonitratehydrogendihydridodioxophosphate(1—)trihydrogentrioxophosphate(3.
-)dihydrogenhydridotrioxophosphate(2—)trihydrogentetraoxophosphate(V)tetrahydrogeni-oxo-hexaoxodiphosphatepoly[hydrogentrioxophosphate(l—)]tetrahydrogenhexaoxodiphosphate(P—P)(4—)dihydrogentetraoxosulfatedihydrogeni-oxo-hexaoxodisulfatedihydrogentrioxothiosulfatedihydrogenhexaoxodisulfate(S—S)dihydrogentetraoxodisulfate(S—S)dihydrogentrioxosulfateNotetheoptionaluseofchargenumbersandoxidationstateswhereitisconsideredhelpful.
Thereisanalternative'acid'nomenclaturethatisbaseduponsimilarprinciples,butisnotasversatile,andisalsousedforoxoacidsoftransitionelements,suchastetraoxomanganicacidandj.
t-oxo-hexaoxochromicacid.
ItisdiscussedfurtherintheNomenclatureofInorganicChemistry,Chapter9.
69CHAPTER4Thehydrogennomenclaturecanalsobeadaptedtoyieldsatisfactorynamesforderivativesobtainedinformalfashionbyreplacingacoordinatedoxogroupfromtheacid.
Asmallselectionisgivenbelow.
Examples18.
H2SO3Shydrogentrioxothiosulfate(2—)19.
HSO3C1hydrogenchlorotrioxosulfate20.
SO2C12dichlorodioxosulfur21.
H[PF6}hydrogenhexafluorophosphate(l—)22.
S02(OCH3)2dimethoxodioxosulfur23.
HOSO2NH2hydrogenamidotrioxosulfate24.
PO(OCH3)3oxotrimethoxophosphorus25.
S02(NH2)2diamidodioxosulfurThesenamesmaynotbetheonlyonesusedforthesecompounds,buttheyaresystematicandeasilycomprehensible.
4.
5SUBSTITUTIVENOMENCLATURE4.
5.
1IntroductionSubstitutivenomenclaturewasdevelopedusingtheconceptsthatgovernedthedevelopmentoforganicchemistry.
However,innomenclaturethetermsubstitutionisusedinaveryrestrictedsense:onlyhydrogenatomscanbeexchangedwithotheratomsorgroupsofatoms.
Thusaparenthydridemustalwaysbethestartingpointofasubstitutionoperation.
Forinstance,thetwomoleculesCH3-ClandCH3-OHarealwaysderivedfromtheparenthydrideCH3-H.
Whenatomsotherthanhydrogenareexchanged,theoperationisinsteadcalled'replacement'andtheresultingnomenclaturecalled'replacementnomenclature.
'Asubstitutivenameconsistsofthenameofaparenthydridetowhichprefixesandsuffixesareattachedasnecessaryfollowingthegeneralpattern:prefixes/nameofparenthydride/suffixesAgivenorganicmoleculeisgenerallycomposedofacarbonskeletonandfunctionalgroups.
Anamematchesastructurewhenthenameoftheparenthydridecorre-spondstotheskeleton,whileprefixesandsuffixesrepresentthefunctionalgroupsandotherstructuralcharacteristics,suchasgeometry.
4.
5.
2Alkanesandthebasicapproachtosubstitutivenames4.
5.
2.
1General.
AlkanesareacyclichydrocarbonsofgeneralformulaCH2+2Thecarbonatomsarearrangedinchainsthatareeitherbranchedorunbranched.
Chainsarecalledcontinuousorunbranchedwhentheyarecomposedof-CH2-groupswithtwoterminal-CH3groups.
Theyarebranchedwhentheycontainmorethantwoterminal-CH3groups.
Inthiscase,atleastonecarbonatommustbejoinedbysinglebondstoatleastthreeothercarbonatoms.
70NAMINGOFSUBSTANCESH3CCH3-CH2-CH2-CH3H3CCH-CH3anunbranchedalkaneabranchedalkane4.
5.
2.
2Unbranchedalkanes.
Unbranchedalkanesarealsocallednormalalkanes.
Thenamesofthefirstfourmembersofthehomologousseriesofunbranchedornormalalkanes,CH2+2'areretainednames.
Theywerecoinedmorethan100yearsago,officiallyrecognisedbytheGenevaConferencein1892,andhavebeenusedeversince.
Therearenoalternativenamesforthem.
Examples1.
methaneCH42.
ethaneCH3-CH33.
propaneCH3-CH2-CH34.
butaneCH3-CH2-CH2-CH3However,highermembersoftheseriesarenamedsystematicallybycombiningtheending-ane,characteristicofthefirstfourmembersandimplyingcompletesatura-tion,withamultiplicativeprefixoftheseriespenta-,hexa-,etc.
ofTable4.
2,whichindicatesthenumberofcarbonatomsconstitutingthechain.
Theletter'a',whichendsthenameofthemultiplicativeprefix,iselided.
Example5.
pent(a)+ane=pentaneCH3-[CH2]3-CH3Thenamesofunbranchedalkanesareoftheutmostimportancebecausethesealkanesaretheparenthydridesusedtonameallaliphaticmolecules,i.
e.
moleculeshavingacarbon-chainskeleton.
4.
5.
2.
3Branchedalkanes.
Branched-chainalkanescanbeconsideredtobeconstitutedofaprincipalchainandside-chains.
Theyarenamedbyusingaprecisesetofoperations:ISelectionoftheprincipalchain,whichwillserveastheparenthydride.
2Identificationandnamingofside-chains,whichwillbetreatedasprefixes.
3Determinationofthepositionofside-chainsontheprincipalchainandselectionoflocantsusingtheruleoflowestlocants.
4Selectionoftheappropriatemultiplicativeprefixes.
5Constructionofthefullname.
Thefollowingexampleillustratesthestep-by-stepconstructionofthenameofthebranchedalkaneshownbelow.
CH3H3C-CH2-CH-CH2-CH2-CH2-CH31234567Theconstructionofthenamebeginsbyselectingthelongestchain,whichhassevencarbonatoms.
Thedisallowedalternativeshavefourorsix.
Theparent7!
CHAPTER4hydrideisthereforeheptane,andthereisonecarbonatominaside-group.
Thisis,ofcourse,amethylgroup.
Puttingthesetogetherleadstothepartialnamemethyl-heptane.
Multiplicativeprefixesarenotneededinthepresentexample,astheprefix'mono'isneverusedinasubstitutivename;finally,thelocant'3'isaddedimmediatelyinfrontofthepartofthenameitqualifies:methyl.
Locantsareseparatedfromotherpartsofnamesbyhyphens.
Thefullnameis3-methylheptane.
Thefollowingthreetrivialnamesarestillused,butonlyfortheunsubstitutedhydrocarbons.
Derivativesarenamedusingsystematicprocedures.
Theseparticularnamesarereferredtoasretainednames.
Examples1.
(CH3)2CH-CH32.
(CH3)2CH-CH2-CH33.
(CH3)CisobutaneisopentaneneopentaneThegeneralcharacteristicsofsubstitutivenomenclaturearenowpresentedinmoredetail.
4.
5.
2.
4Namesofalkylgroups.
Unbranchedalkylgroupsaremonovalentgroupscreatedbythesubtractionofahydrogenatomfromaterminal-CH3oftheunbranchedalkaneconsideredtobetheparenthydride.
Theyarenamedbyreplacingtheending-aneinthenameoftheparenthydrideby-yl.
Thecarbonatomwiththefreevalencealwaysreceivesthesmallestlocant,namely'1'.
Thesealkylgroupsarecallednormalorunbranched.
Examples1.
methyl—CH32.
ethyl—CH2-CH33.
propyl-CH2-CH2-CH34.
decyl—CH2-[CH2]8-CH3Branchedalkylgroupsarenamedbyprefixingthenamesoftheside-chainstothatofthelongestunbranchedalkylgroup.
Example5.
CH3-CH2-CH(CH3)-CH2-CH2-3-methylpentyl54321Thefollowingnamesarestillused,butonlyfortheunsubstitutedgroups.
Theseparticularnamesarealsoreferredtoasretainednames.
Iftherearesubstituentswithinthesegroups,systematicproceduresmustbefollowed.
Examples6.
(CH3)2CH-isopropyl7.
(CH3)2CH-CH2-isobutyl8.
CH3-CH2-CH(CH3)-sec-butyl9.
(CH3)3C-tert-butyl72NAMINGOFSUBSTANCES10.
(CH3)2CH-CH2-CH2—isopentyl11.
CH3-CH2-C(CH3)2—tert-pentyl12.
(CH3)3C-CH2—neopentylThegroupsattachedtotheprincipalchainarecalledsubstituents,andthesemaybesimpleorcomplex.
Simplesubstituentsareformeddirectlyfromparenthydrides;whenasimplesubstituentisitselfsubstituted,itbecomescomplexasaconsequence.
Normalalkylgroupsaresimplesubstituents;branchedalkylgroupsarecomplexsubstituents.
However,asexceptionsthenamesisopropyl,isobutyl,sec-butyl,tert-butyl,isopentyl,tert-pentylandneopentylaretakentorefertosimplesubstituents.
4.
5.
2.
5Multiplicativeprefixes.
Multiplicativeprefixes(Table4.
2)areusedwhenmorethanonesubstituentofagivenkindispresentinacompoundorgroup.
Thenameofthesubstituentiscitedasaprefix,andtwosetsofmultiplicativeprefixesareused,dependingonwhetherthesubstituentissimpleorcomplex.
Basicmultiplicativeprefixesdi-,tn-,tetra-,etc.
areusedwiththenamesofsimplesubstituentsandretainednames.
Differentormodifiedprefixesareusedwithcomplexsubstituents:bis-,tris-,tetrakis-;fromtetrakis-onwardstheending-kisisattachedtothebasicmultiplicativeprefix,givingpentakis-,hexakis-,etc.
(comparetheuseincoordinationnomenclature).
Examples1.
3,3-dimethylpentane2.
5,5-bis(l,2-dimethylpropyl)nonane3.
4,4-diisopropylheptaneor4,4-bis(1-methylethyl)heptaneIngeneral,chemistsliketouseretainednames.
Theshorteranapprovedname,thebetter.
4.
5.
2.
6Lowestlocants.
Locantsareusedtoindicatethepositionofsubstituentsinacompoundorgroup.
Analmostinvariableruleisthatlocantsareselectedsothatthesetusedhasthelowestpossiblevalues.
Lowestlocantsaredeterminedbycomparingalternativesetsoflocants.
Whencomparedterm-by-termwithotherlocantsets,eachinorderofincreasingmagnitude,asetoflowestlocantshasthelowesttermatthefirstpointofdifference;forexample,2,3,6,8islowerthan3,4,6,8or2,4,5,7.
Examples1.
2.
12345123456789543219876543212,3-dimethylpentane2,4,8-tnimethylnonane(theset2,3islowerthan3,4)(theset2,4,8islowerthan2,6,8)73CHAPTER44.
5.
2.
7Alphabeticalorderforcitationofdetachableprefixes.
Prefixesareusedtonamesubstituents,asdiscussedabove.
Suchprefixesarecalleddetachableprefixes.
Thereisafurtherclassofprefixdescribedasnon-detachable.
Anexampleiscyclo-,asincyclohexyl,whichisdifferentinstoichiometryfromtheunmodifiedhexyl.
Non-detachableprefixesareusedtomodifypermanentlythenameofaparenthydrideandthustocreateanewparenthydride(seealsosection4.
5.
3.
4,p.
78).
Whenconstructinganame,detachableprefixesarecitedinfrontofthenameoftheparenthydrideinalphabeticalorder.
Thenamesarealphabetisedbyconsideringthefirstletterofeachname:'m'inmethyl,'b'inbutyl,'d'inl,2-dimethylpropyl.
Inretainednames,thefirstnon-italicisedletterisconsidered:'i'inisobutyl,'n'inneopentyl,but'b'intert-butyl.
Theassemblyofthecomponentstoconstructafullnamestartsbyattachingthenamesofthedetachableprefixesinalphabeticalordertothenameoftheparenthydride.
Then,andonlythen,necessarymultiplicativeprefixesareintroduced,withoutchangingthealphabeticalorderobtainedpreviously.
Finally,locantsareinserted.
Examples1.
4-ethyl-2-methylhexane2.
4-ethyl-2,2-dimethylhexane3.
6,6-bis(l,2-dimethylpropyl)-3,4-dimethylundecaneInsomenameswithmorethanonedetachableprefix,asetoflocantscanbeattributedinmorethanoneway,aswiththelocants3and5inthefollowingexample.
Insuchacase,thelowstlocantisallocatedtothesubstituentcitedfirst.
Example4.
3-ethyl-5-methylheptaneAsaconsequence,thegeneralpatternofsubstitutivenamesbecomes:detachablenon-detachablenameofsuffixesprefixesprefixesparenthydride4.
5.
2.
8Criteriafortheselectionoftheprincipalchain.
Itisnecessarytolaydownrulesfortheselectionoftheparenthydridewhereitsidentityisnotself-evident.
ThecriteriafortheselectionoftheprincipalchainarelistedinAppendix1.
Theyareverygeneral,astheydealwithsaturatedandunsaturatedmolecules,andincludetheuseofprefixesandsuffixestocharacteriseallkindsofsubstituent.
Inthecaseofalkanes,neithercriterion(a)(thereisnoprincipalcharacteristicgroup)norcriterion(b)(thereisnounsaturation)isrelevant.
Thethirdcriterion(c)isapplicable:theprincipalchainmustbethelongest.
Thenextrelevantcriterion(h)isappliedwhencriterion(c)doesnotpermitadefinitivechoicetobemade.
Accordingtocriterion(h),theprincipalchainwillthenbethemostsubstitutedamongstallthoseofequallengththatareconsidered.
74NAMINGOFSUBSTANCESExamplesCH3CH-CH3CH-CH3CH3—CH2—CH2—CH2—CH—CH2—CH2—CH2—CH35-(1,2-dimethylpropyl)nonaneCH3CH2CH2CH2CH3CH3CH3—CH2—CH2—CH2-CH—CH—CH—CH2—CH35-butyl-3,4-dimethylnonane4.
5.
3Cyclicparenthydrides4.
5.
3.
1General.
Continuous-chainalkanesarethesoleparenthydridesforallcompounds,theskeletonofwhichiscomposedofchains.
Cyclicparenthydridesaremorediverse.
Innomenclature,theyareclassifiedaccordingtotheirstructureascarbo-cycles(composedofcarbonatomsonly)andheterocycles(composedofcarbonatomsandotheratoms,suchasN,0andSi).
Theyarealsoclassifiedassaturatedandunsaturated.
Saturatedcycleshavethemaximumnumberofhydrogenatomsattachedtoeveryskeletalatom,asjudgedbyaprespecifiedvalence;unsaturatedcycleshavefewerhydrogenatomsandmultiplebondsbetweenpairsofatoms.
Variousdegreesandkindsofunsaturationarepossible.
Unsaturationmaybecumulative(whichmeansthatthereareatleastthreecontiguouscarbonatomsjoinedbydoublebonds,C=C=C)ornon-cumulative(whichisanotherarrangementoftwoormoredoublebonds,asin-C=C-C=C-).
Innomenclature,unsaturatedcyclicparenthydrideshave,byconvention,themaximumnumberofnon-cumulativedoublebonds.
Theyaregenericallyreferredtoasmancudes—derivedfromtheacronymMANCUD,theMAximumNumberofnon-CUmulativeDoublebonds.
Fourclassesofcyclicparenthydridearethereforerecognised:CccosaturatedsaturatedcarbocyclicheterocycliccarbocycleheterocyclemancudemancudeBytheendof1996morethan105000differentringsandringsystemshadbeenencountered(P.
M.
Giles,ChemicalAbstractsService,personalcommunication).
75CHAPTER4Forcomparison,onlyafewdozenalkanesaredesignatedasparenthydrides.
Over73000ringsandringsystemsaremancudesandabout10000arecarbocycles.
Asecondgeneralfeatureofthisnomenclatureistheuseofprefixestomodifythenamesofbasicparenthydridesinordertocreatenewparenthydrides.
Conse-quently,theseprefixesarenon-detachable,permanentlyattachedtothenameofthebasicparenthydride,andaretreatedinalphabeticprocedureslikenon-detachableprefixesinalkanenomenclature.
Amongotherthings,thesenon-detachableprefixesareusedtoindicatetheconversionofachaintoaring(e.
g.
cyclo-,asincyclohexane;seeSection4.
5.
3.
2),theopeningofrings(e.
g.
seco-,asinsomenaturalproductnames;seeChapter7,section7.
5,p.
122),thefusionofrings(e.
g.
benzo-,asinbenzopyrene)andthereplacementofcarbonatomsinringsbyheteroatoms,thustransformingcarbocyclesintoheterocycles(e.
g.
phospha-,asinphosphacycloun-decane;seeSection4.
5.
3.
3,p.
77).
4.
5.
3.
2Monocyclicparenthydrides.
Saturatedmonocycliccarbocyclesaregenericallycalledcycloalkanes.
Individualringsarenamedbyaddingthenon-detachableprefixcyclo-tothenameofthenormalalkanehavingthesamenumberofcarbonatoms.
Thecarbocyclicmancudehavingsixcarbonatomsisnamedbenzene.
HighermancudehomologueshavingthegeneralformulaCHorCH+1arenamed[x]annulenes,xrepresentingthenumberofcarbonatomsinthering.
AnnuleneswithanoddnumberofcarbonatomsarefurthercharacterisedbythesymbolHtosignalthepresenceofaspecialhydrogenatomcalled'indicatedhydrogen'.
Thissymbolisanon-detachableprefix.
ExamplesJT72.
:J:64.
cyclohexanebenzene1H-[7]annulene[8]annuleneThenumberingofmonocyclichydrocarbonsisnotfixed,asanycarbonatommayreceivethelocant'1'.
Non-detachableprefixeshavepriorityforlowestlocants,andifthisis'indicatedhydrogen'itmustreceivethelocant'1'.
Theimportanceofthepresenceofan'indicatedhydrogen'isevidentinsubstitutedrings.
Examples5.
6_126.
65)34ethylbenzene2-methyl-1H-[7]annulene7654NAMINGOFSUBSTANCES4.
5.
3.
3Heterocyclicparenthydrides.
Thesecompoundsformalargeanddiversegroup.
Thenamesoftheseparenthydridesareusuallyformedsystematically.
However,some50trivialnamesareretainedandusedinpreferencetotheirsystematiccounterparts.
Examples3.
5J2pyrrolefuranthiophenepyridineThetwomostimportantmethodsfornamingheterocyclicparenthydridesaretheextendedHantzsch—Widmansystemandreplacementnomenclature.
TheextendedHantzsch—Widmansystemisusedtonamemonocyclesofsatu-ratedandmancuderingswithbetweenthreeandtenmembers,inclusive.
Thenamesarecomposedoftwoparts:non-detachableprefix(es),indicatingtheheteroatom;andastemindicatingthesizeofthering.
Namesofprefixes(called'a'prefixes)arelistedinTable4.
8andnamesofstemsinTable4.
9.
Thechoiceofastemcorrespondingtothegroupsofcompoundswithsixringatomsanddesignated6A,6Bor6CinTable4.
9isdeterminedbytheatom,thenameofwhichimmediatelyprecedesthenameofthestem:6AO,S,Se,Te,Bi,Hg6BN,Si,Ge,Sn,Pb6CB,P,As,SbNamesareformedbyelidingthefinalletter'a'ofthe'a'prefixbeforeitisattachedtothestem.
Whenoneheteroatomispresent,thelocant'1'isattributedtotheheteroatom.
Inmanycases,an'indicatedhydrogen'isnecessarytodescribethestructurewithaccuracy.
Thepresenceofmorethanoneheteroatomofanytypeisindicatedbyamultiplicativeprefix(di-,tn-,etc.
).
Iftwoormorekindsofheteroatomoccurinthesamename,theorderofcitationistheorderoftheirappearanceindescendingTable4.
8.
ThenumberingstartsfromtheheteroatomcitedfirstinTable4.
8,givingthelowestpossiblelocantstootherheteroatoms.
Examples1117N22N613A26.
6Q37.
35oxirane2H-azepine1,2,4-triazine1,2-oxathiolaneReplacementnomenclatureisusedtonameheteromonocyclesthatcontainmorethantenatoms.
Indevelopingareplacementname,carbonatomsareregardedasexchangedforheteroatoms.
Thenon-detachableprefixes(Table4.
8)areusedtoindicatetheexchange.
Cycloalkaneorannulenenamesarethebasesfortransforma-tionintothenameofaheterocycle.
77CHAPTER4Table4.
8The'a'prefixesusedinHantzsch—Widmannomenclature.
ElementOxidationstatePrefixElementOxidationstatePrefixOxygeniioxaBismuthinbismaSulfuriithiaSiliconivsilaSeleniumiiselenaGermaniumivgermaTelluriumiitelluraTinivstannaNitrogeninazaLeadivplumbaPhosphorusinphosphaBoronInboraArsenicinarsaMercuryiimercuraAntimonyinstibaExamplesphosphacycloundecane10.
8f"\2sila[12]annulenePolycyclicparenthydrides.
Theseareclassifiedasbridgedpolyalkanes(alsoknownasvonBaeyerbridgedsystems,fromthenomenclaturesystemdevelopedtonamethem),spirocompounds,fusedpolycyclicsystemsandassembliesofidenticalrings.
Thefoursystemsmaybeeithercarbocyclicorheterocyclic.
Indevelopingtheirnames,thefollowingprinciplesareused.
Thenon-detachableprefixesbicyclo-,tricyclo-,etc.
andspiro-characterisethebridgedandthespirosystems.
Numbersinsquarebracketsgivenecessaryinforma-tionaboutthelengthsandpositionsofthebridgesinthesepolycyclicsystems.
78RingsizeUnsaturated(mancude)Saturated(mancude)3irene*-iranet4-etc-ctanet5-ole-olanet6A-inc-ane6Bt-inc-inane6Ct-mine-inane7-epine-epane8-ocine-ocane9-onine-onane10-ecine-ecane*Thetraditionalstem'irine'maybeusedforringscontainingnitrogenonly.
tThetraditionalstems'iridine','etidine'and'olidine'arepreferredforringscontainingnitrogen.
fForringsizesix,theterminations6Arefertocompoundsof0,5,Se,Te,BiandHg;theterminations6BrefertocompoundsofN,Si,Ge,SnandPb;andtheterminations6CrefertocompoundsofB,P,AsandSb.
4.
5.
3.
4Table4.
9NamestemsusedinHantzsch—Widmannomenclature.
ExamplesNAMINGOFSUBSTANCES2.
11::tricyclo[4.
2.
0.
02'5]octane3.
8(JQ9104spiro[4.
5]decaneHeterocyclicsystems,whichcanberegardedasformedbyreplacementofcarbonatomsintheparentsdescribedabovebyheteroatoms,arenamedbyreplacementnomenclature.
Examples2-azabicyclo[2.
2.
2]octane101205.
3750842,4,8,10-tetraoxaspiro[5.
5]undecaneFusedpolycyclicsystemsareverynumerousanddiverse.
Theyarenamedusingthestructuresandnamesoftheirsmallercomponentsandtheconceptofortho-fusion,whichispurelyaformaloperationencounteredinnomenclature.
Thisconceptisessentialtothenamingoflargersystems,andistheformationofonebondbythecondensationoftwobondsbelongingtotwodifferentcyclicsystems,oneofthembeingamancudering.
About60fusedpolycyclicsystemshavetrivialnamesthatareretainedforpresentuse.
Examples6H281N8.
93Somefusedsystemsarenamedsystematicallybyusingamultiplicativeprefixinfrontofanendingrepresentingawell-definedarrangementofcycles.
Forinstance,theending-acene,takenfromanthracene,indicatesalineararrangementofbenzenerings,asintetracene,pentacene,etc.
79l.
J8CH-CH36.
propane-1,3-diyl—CH2-CH2-CH2—4.
5.
4.
3Selectionoftheprincipalchaininunsaturatedbranchedacyclichydrocarbons.
Aprincipalchainmustbechosenuponwhichto'basethenameofbranchedunsatu-ratedacyclichydrocarbons.
ThegeneralcriterialistedinTable4.
10areapplied.
Thosethatarespecificallyrelevanttopo!
yenesandpolyynesare:criterion(b),whichisthemaximumnumberofdoubleandtriplebondsconsideredtogether;criterion(c),whichisthemaximumlength;criteria(d),(f)and(g);criterion(h),whichisthemaximumnumberofsubstituentscitedasprefixes;andcriteria(i)and(j).
ExamplesH2C=CH—C=CH2H2C=C-CH2-CH2-CH2-CH31.
I2.
IC6H13C2H52-hexylbuta-l,3-diene2-ethylhex-1-ene(criterionb)(criteriabandc)82NAMINGOFSUBSTANCESC5H11CH33.
IIH2C=C-CH2-CH2-CH2-CH—CH36-methyl-2-pentylhept-1-ene(criteriab,candh)Table4.
10Seniorityofchains(theprincipalchain)Whenachoicehastobemadeofprincipalchaininanacycliccompound,thefollowingcriteriaareappliedsuccessively,intheorderlisted,untilasinglechainisleftunderconsideration.
Thisisthentheprincipalchain.
(a)Selectthechain(s)thathas(have)themaximumnumberofsubstituentscorrespondingtotheprincipalgroup.
(b)Ifthisisnotdefinitive,selectthechainthathasthemaximumnumberofdoubleandtriplebonds,consideredtogether.
If(a)and(b)togetherarenotdefinitive,thefollowingcriteriaarethenappliedinorderuntilonlyonechainremainsunderconsideration.
(c)Chainwithmaximumlength.
(d)Chainwithmaximumnumberofdoublebonds.
(e)Chainwithlowestlocantsfortheprincipalgroups,whicharethosecitedassuffixes.
(f)Chainwithlowestlocantsformultiplebonds.
(g)Chainwithlowestlocantsfordoublebonds.
(h)Chainwithmaximumnumberofsubstituentscitedasprefixes.
(i)Chainwithlowestlocantsforallsubstituentsintheprincipalchaincitedasprefixes.
U)Chainwiththesubstituentthatcomesfirstinalphabeticalorder.
4.
5.
5Assembliesofdifferentrings,andofringswithchainsAssembliesofdifferefltringsaregivensubstitutivenamesinwhichoneringischosenastheparenthydride,andtheotherisdenotedbyaprefix.
Thenamesofmono-ordivalentcyclicsubstituentsareformedbyaddingthesuffix-ylor-ylidene,asappropriate,tothenameofthecycle,withtheexceptionofcycloalkanes,forwhichthesuffixesreplacetheending-aneratherthanaddingtoit.
Notethatdesignationssuchas>—andC—areusedtoindicateafreevalencewhenever>—andC—mightotherwisebetakentoindicateanappendedmethylgroup.
Examples1.
H2CCH22.
23.
/\4.
IIIH2CCHH2CCH2cyclopentylspiro[3.
4]octan-5-yloxiran-2-ylphenyl83CHAPTER4cyclopent-2-en-1-yl6.
Xsilinane-2,3-diylH2C—CH2HC—Ccyclobutylidene4.
5.
64.
5.
6.
184TheprincipalringisselectedusingthecriteriainTable6.
1.
Forinstance,heterocycleshavepriorityovercarbocyclesandunsaturatedsystemshavepriorityoversaturatedsystems.
ExamplesCompoundscomposedofringsandchainsarealsonamedusingsubstitutivenomenclature.
Thering,whethercarbocyclicorheterocyclic,isalwaysselectedtobetheparenthydride.
ExamplesCH2CH10.
(CH5)CHNTrivialnamesofsubstitutedbenzenesretainedforpresentuseincludetoluene,styreneandstilbene,butonlyforderivativeswhensubstitutinginthering(seeSection4.
5.
6.
2andTable4.
13).
NomenclatureoffunctionalisedparenthydridesTheuseofsuffixesandprefixes.
Thegroupsthataretypicalofthevariousclassesoforganiccompound,suchas,0-OHinalcohols,>C=Oinketonesand—C(OHarecalledcharacteristicgroupsorfunctions.
incarboxylicacids8.
2-(azulen-2-yl)pyridine9.
cyclohexylbenzene1,1'-methylenedibenzene4-vinylpyridine12.
hexylcyclopropaneNAMINGOFSUBSTANCESThenamesofcharacteristicgroupsarecitedassuffixesorprefixeswhentheseclassesoforganiccompoundarenamedusingsubstitutivenomenclature.
Ifonlyonecharacteristicgroupispresent,thenitsnameiscitedasasuffix.
Ifmorethanonetypeofcharacteristicgroupispresent,onemustbechosenastheprincipalgroupanditsnameisthencitedasasuffix.
Thenamesofallothercharacteristicgroupsarecitedasdetachableprefixes.
However,somecharacteristicgroupsareexpressedinanameasprefixesonlyandarenevercitedassuffixes.
SuffixesandprefixesarelistedinTables4.
11and4.
12.
Thedetailedusageisexemplifiedinthefollowingdiscus-sion.
Table4.
11Somecharacteristicgroupswithnamesalwayscitedasprefixesinsubstitutivenomenclature.
ClassGroupPrefixClassGroupPrefixHalogencompoundsFClfluoro-chloro-EthersNitrocompoundsO-RNO2R-oxy-nitro-BrIbromo-iodo-NitrosocompoundsNOnitroso-Table4.
12Somecharacteristicgroups*withnamescitedassuffixesorprefixesinsubstitutivenomenclature,presentedindecreasingorderofseniority(seeTables4.
10and6.
1).
ClassSuffixPrefixGroupRadicalsAnionsCationsseeTable4.
14Carboxylicacids-oicacid-carboxylicacidcarboxy-tcarboxy--(C)OOH-COOHSulfonicacids-sulfonicacidsulfo--SO2OHEsters—j(R-oxy)-oxo-R-oxycarbonyl--(C)OOR-COORAcylhalides—halo-oxo-halocarbonyl--(C)OHa1-COHa1Amides-amide-carboxamideamino-oxo-aminocarbonyl--(C)ONH2-CONH2Nitriles-nitrile-carbonitrilecyano-cyano--(C)N-CNAldehydes-a!
-carbaldehydeoxo-formyl--(C)HO-CHOKetones-oneoxo-=0Alcohols,phenols-olhydroxy--OH*Thecarbonatomsinparenthesesinsomegroupsbelongtotheparenthydride,normallyachain.
Iftherearenoparenthesesintheformula,thenameofthegroupasawholeisaddedtothenameoftheparenthydride.
Whenattachedtoaring,thegroups-COOHand-CNarenevertreatedas-(C)OOHor-(C)N.
Ifanunbranchedchainisdirectlylinkedtotwoormorecarboxygroups,thenameisbaseduponthatchainandthecarboxygroupsaretreatedassubstituents-COOHandnotas(C)OOH.
fSeediscussionoffunctionalclassnomenclature,Chapter4,Section4.
6(p.
96).
85CHAPTER44.
5.
6.
2Namesofcharacteristicgroupsalwayscitedasprefixes.
Thenamesofthetwopolyhalogenatedethanes,aandb,areagoodillustrationoftheapplicationoftheruleoflowestlocantsandofthealphabeticalordertoassignlowestlocants.
Examples1.
ClFC-CHBrIa2-bromo-l-chloro-l,l-difluoro-2-iodoethane2.
BrF2C-CC1FIbl-bromo-2-chloro-l,l,2-tnfluoro-2-iodoethaneInmonocyclichydrocarbons,thelocant'1'isomitted,butitisnecessaryinpolysubstitutedcompounds.
ExampleschlorocyclohexaneNO2l-fluoro-2,4-dinitrobenzeneNO2l,2-bis(2,2,2-trifluoroethyl)cyclopentaneWhenthenumberingispredeterminedbythenatureoftheparenthydride,asinpolycyclichydrocarbonsandinheterocycliccompounds,lowestlocantsarestilltherule.
ExamplesC'6.
/l-chloroazuleneH2Sil2F7.
2,4-difluorosilinane86NAMINGOFSUBSTANCESNO298.
"%%%109-nitroanthraceneIfachoicehastobemade,lowestlocantsareassignedfirsttoheteroatomsincycles,thentopositionsofunsaturationand,finally,tosubstituentscitedasdetachableprefixes.
ExamplesBr10.
1l-bromo-l-azacyclotridec-4-ene4-bromo-l-oxacyclotridec-7-eneNormally,thenamesofallsubstituentsarecitedasprefixesinfrontofthenameoftheparenthydride,buttherearethreeexceptions.
Thenamesofthreesubstitutedbenzenes—toluene,styreneandstilbene—areretainedandcanbeusedtonamesubstitutedderivatives,aslongasthesubstitutionisonlyonthering.
Examples11.
L)12.
Br4%%13.
2-chlorotoluene4-bromostyrene1-bromo-2,3-dimethylbenzene(not3-bromo-o-xylene)87CHAPTER44.
5.
6.
3Namesofcharacteristicgroupscitedassuffixesorprefixes.
Insubstitutivenomencla-ture,asuffixmustbeusedwheneverpossibleforthepreferredfunctionalgroup.
Prefixesareusedtonameallcharacteristicgroupsexceptprincipalfunctionalgroups.
Lowestlocantsandmultiplicativeprefixesdi-,tn-,tetra-,etc.
areusedfollowingthegeneralrulesstatedinSection4.
5.
2(p.
70).
SuffixesandprefixesarelistedinTables4.
11and4.
12.
Monofunctionalcompoundsarenamedasfollows:1.
CH3-CH2-CH2OHpropan-i-ol2.
CH3-CO-CH2-CH2-CH3pentan-2-one3.
CH3-CH(OH)-CH(OH)-CH3butane-2,3-diol4.
cyclopentanolThesuffixes-oicacid,-al,-amideand-nitnieareusedtonameacycliccompoundshavingoneortwocharacteristicgroups.
Locantsarenotnecessary,asthesegroupsmustbeattheendofachain.
Thesuffixes-carboxylicacid,-carbaldehyde,-carboxamideand-carbonitrileareusedwhenmorethantwogroupsareattachedtochainsoroneormoregroupsareattachedtocycles.
Examples5.
CH3-CH2-COOHpropanoicacid6.
OHC-CH2-CH2-CHObutanedial7.
CH2(COOH)-CH(COOH)-CH2(COOH)propane-i,2,3-tricarboxylicacidCHO8.
cyclopentanecarbaldehyde9.
CH3-[CH2]3-CONH2pentanamide10.
NC-[CH2]4-CNhexanedinitnileCONH2ii.
cyclohexanecarboxamide12.
cI"I1CNpyridine-2-carbonitrileSuffixesandprefixesarenecessarytonamestructureswithdiscontinuities,forinstancewhencharacteristicgroupsaresituatedonside-chains,orwhenthecarbonskeletoniscomposedofringsandchains.
Aprincipalcomponent,ringorchain,mustbechosen.
TheprincipalchainischoseninaccordancewiththeselectioncriterialistedinTable4.
10andisthechainsupportingthegreatestnumberof88NAMINGOFSUBSTANCEScharacteristicgroups.
Ifthisisnotdecisive,thelongestchain—criteria(a)and(c)—ischosen.
Example13.
H2OH3-(hydroxymethyl)octane-HOCH2—CH2-CH-CH2-CH2-CH2-CH2-CH2OH1,8-diolInthecaseofstructureshavingbothringsandchains,theprincipalcomponentmustalsohavethemostcharacteristicgroups.
ExamplesOH214.
2OH1-(2-hydroxyethyl)cycloheptane-l,2-diol15.
HO3-(4-hydroxycyclohexyl)propane-l,2-diolInthenamesofamines,thegeneraluseofsuffixesandprefixesisnotalwaysobserved.
Normally,thesuffix-aminewouldbeaddedtothenameoftheparenthydrideandengendernamessuchasmethanamine(CH3-NH2).
Furthersubstitutiononthenitrogenatomwouldthenbeindicatedbyprefixes,leadingtonamesthatappearverycumbersome,suchasN-methylmethanaminefor(CH3)2NHandN,N-dimethylmethanaminefor(CH3)3N.
Thetraditionalnamesofmethylamine,di-methylamineandtrimethylaminearemuchsimpler.
Inthesenames,thetermamineisnotasuffix.
Itis,infact,thenameoftheparenthydride,NH3,whichnowservesasthebasisofsubstitutivenames.
Namessuchasdiethylamineandtributylaminearerepresentativeofthepreferrednomenclature.
Diaminesarenamedaccordingly,aswithethane-1,2-diamineforH2N-CH2-CH2-NH2andpropane-l,3-diamineforH2N-[CH2]3-NH2.
Thereareallowedalternativesfortheselasttwocompounds:ethylenediamineandpropane-1,3-diyldiamine.
Mancudeketonesarealsoofspecialinterest,asthe=0groupcanonlybeaccommodatedonthecarbonframeworkifthereisa-CH2-toreplaceintheparenthydride.
Foramancudehydride,itisnecessarytoconsiderfirstthatadoubleortriplebondissaturated,andthenthat>CH2becomesCO.
ThisleavesanextraHonaneighbouringcarbon.
Takenaphthaleneasanexample;thename1,2-dihydronaphthalen-2-oneaccuratelydescribesthetwonecessaryoperationsthatareneeded:saturationandsubstitution.
Aquickerway,leadingtoasimplername,istoconsiderthatthesaturationandthesubstitutionareconcomitant,withtheresultthatonlyonehydrogenatomhasbeenaddedtothecyclicsystem.
ThisadditionalhydrogenatomiscalledanaddedhydrogenanditisrepresentedinthenamebythesymbolHtogetherwiththeappropriatelocant.
89CHAPTER4Examples16.
()6:4H-pyranpyran-4-one17.
0naphthalenel,2-dihydronaphthalene1,2-dihydronaphthalen-2-oneornaphthalen-2(1H)-oneThesuffix-oneisalsousedtonameclassesotherthanketones.
Forinstance,thelactonesandthelactams,whichareheterocyclicsystems,canbenamedbyaddingthesuffix-onetothenameofthecorrespondingheterocycle.
Specificsuffixes-olactoneand-olactammayalsobeusedinsimplecases.
Examples18.
tetrahydrofuran-2-oneorbutano-4-lactoneNH19.
1-azocan-2-oneorheptano-7-lactam20Twofurtherrulesareneededtonamepolyfunctionalcompounds:1Therecanbeonlyonetypeofcharacteristicgroup,theprincipalgroup,whichiscitedasasuffix.
Theothergroupsmustbecitedasprefixes.
2TheprincipalgroupisselectedusingtheprioritiesofTable4.
12.
Examples20.
CH3-CO-CH2-CH(OH)-CH34-hydroxypentan-2-one21.
CH3-C(O)-C(O)-C(O)OH2,3-dioxobutanoicacid22.
H2N-CH2-CH2-OH2-aminoethanol23.
OHC-CH(CH3)-CH2-CH2-COOH4-methyl-5-oxopentanoicacid24.
OHCCOOH4-formylcyclohexane-1-carboxylicacid90NAMINGOFSUBSTANCES25.
H2N-CO-CH2-CH2-COOH4-amino-4-oxobutanoicacidCOOH26.
2-(aminocarbonyl)benzoicacidCONH227.
NC-CH2-CH2-CH2-CONH24-cyanobutanamideCOOH28.
NC—-"3-cyanocyclobutane-l-carboxylicacid4.
5.
7NamesoffunctionalparenthydridesParenthydridesarealkanesandmancudeshavingtrivialorsystematicnames,andgroupsderivedfromtheseparenthydridesareindicatedbynon-detachableprefixes.
However,thereisagroupoffunctionalparenthydridesthatisstillknownundertrivialnames.
Aceticacidisanexample.
Thesefunctionalparenthydridenamesareusedlikeordinarycyclicandacyclicparenthydridenames,withoneimportantdifference.
Astheyalreadycontaincharacteristicgroupsprioritisedtobecitedassuffixes,theycanbefurtherfunctionalisedonlybycharacteristicgroupshavinglesserpriority,whichwillthenbecitedasprefixes.
Thereareveryfewsuchfunctionalparenthydridenamesrecognised,butthenamesofsomearegivenhereduetotheirimportanceinnomenclature.
HydrocarbonsHCCHacetyleneHydroxycompoundsC6H5OHphenolC'arbonylcompoundsCH3-CO-CH3acetoneCarboxylicacidsCH3-COOHaceticacidCH2=CH-COOHacrylicacidHOOC-CH2-COOHmalonicacidHOOC-CH2-CH2.
COOHsuccinicacidH2N-COOHbenzoicacidC6H5-COOHoxamicacidH2N-CO-COOHcarbamicacidHOOC-COOHoxalicacidCOOHIJJphthalicacidCOOH91CHAPTER4COOHHOOCisophthalicacidterephthalicacidAminesC6H5-NH2anilineAcyclicpolynitrogencompoundsH2N-C(=NH)-NH2H2N-NH2H2N-CO-NH2Ringsubstitutedbenzenes,substitutioninringonlyC6H5-CH3tolueneC6H5-CH=CH2styreneOthernamesareretainedforreferringtounsubstitutedcompoundsonly.
Com-poundsderivedfromthembysubstitutionmustbenamedsystematically.
Thenamesareretainedbecauseoftheirwideuseinbiochemicalandinpolymernomenclature.
Afewexamplesaregivenhere.
HydroxycompoundsHO-CH2-CH2-OHHO-CH2-CH(OH)-CH2-OHpropionicacidglutaricacidadipicacidmethacrylicacidformicacid(fornomenclaturepurposes,thehydrogenatomlinkedtocarbonisnotregardedassubstitutable)AminesH3C-C6H4-NH2toluidine(1,2-,1,3-and1,4-(o-,m-andp-)isomers)Thenamespropanoicacid(systematic)andpropionicacid(retained)arebothapprovedfortheunsubstitutedacid.
However,theacidCl-CH2-CH2-COOHmustbenamedsystematicallyas3-chloropropanoicacid.
TheacidCH3-CH(OH)-COOHisknownaslacticacid,ifunsubstituted;whenitissubstitutedinposition3,forexamplewithchlorine,thenamebecomes3-chloro-2-hydroxypropanoicacid.
Namessuchas3-chloro-2-hydroxypropionicacidor3-chiorolacticacidarenotacceptable.
guanidinehydrazineureaethyleneglycolglycerolCarboxylicacidsCH3-CH2-COOHCH3-CH2-CH2-COOHHOOC-[CH2}3-COOHHOOC-[CH2]4-COOHH2C=C(CH3)-COOHH-COOHbutyricacid92NAMINGOFSUBSTANCESRetainednamesofcarboxylicacidsmayalsobemodifiedtonameamides,nitrilesandaldehydes,bychangingthe-icacidendingto-amide,-onitrileor-aldehyde.
Namessuchasformaldehyde,acetonitrileandpropionamideresult.
Ofthese,onlyacetonitrilemaybetreatedasafunctionalparenthydride.
AmorecompletelistofretainedtrivialnamesisshowninTable4.
13.
Table4.
13Sometrivialnamesstillretainedfornamingorganiccompounds.
(A)Namesoffunctionalparenthydrides,usablewithunlimitedorlimitedsubstitution,asindicatedHydrocarbonsH2C=C=CH2EthersC6H5-OCH3Carbonylcompounds(ketonesandpseudoketones)CH2=C=O0alleneanisole(forringsubstitutiononly,notmethylsubstitution)keteneanthraquinone(9,10-isomerdepicted)benzoquinone(1,4-isomershown)naphthoquinone(1,2-isomershown)isoquinolone(1-isomershown)pyrrolidone(2-isomershown)quinolone(2-isomershown)Continuedonp.
94.
9300IJ'OCHAPTER4Table4.
13(Continued.
)HydroxycompoundsHO-CH2-CH(OH)-CH2-OHC(CH2OH)4(CH3)2C-(OH)-C(OH)-C(CH3)2glycerolpentaerythritolpinacolcresol(1,4-isomershown)94OHOHOHHO02NNO2NO2pyrocatecholresorcinolhydroquinonepicricacidContinued.
CarboxylicacidsCH3-COOHaceticacidCH2=CH-COOHacrylicacidHOOC-CH2-COOHmalonicacidHOOC-CH2-CH2-COOHsuccinicacid(B)NamesretainedonlyfordesignatingunsubstitutedcompoundsCH3HO''thymolcarvacrolNAMINGOFSUBSTANCESTable4.
13(Continued.
)CarboxylicacidsCH3-CH2-COOHpropionicacidCH3-CH2-CH2-COOHbutyncacidHOOC-[CH2]3-COOHglutaricacidHOOC-[CH2]4-COOHadipicacidH2C=C(CH3)-COOHmethacrylicacidHOOC-[CH(OH)]2-COOHtartaricacid(HO)H2C-CH(OH)-COOHglycericacidCH3-CH(OH)-COOHlacticacid(HO)H2C-COOHglycolicacidOHC-COOHglyoxylicacidCH3-CO-CH2-COOHacetoaceticacidCH3-CO-COOHpyruvicacidCH2-COOHC(OH)-COOHcitricacidCH2-COOH(NOOC-CH2)2N-CH2-CH2-N(CH2-COOH)2ethylenediaminetetraaceticacidAminesH3C-C6H4-NH2toluidine(1,2-,1,3-and1,4-(o-,m-andp-)isomers)HydrocarbonsH2C=C(CH3)-CH=CH2isopreneH3C-C6H4-CH3xylene(1,2-,1,3-and1,4-(o-,m-andp-)isomers)(CH3)2CH-C6H5cumeneH3C-C6H4-CH(CH3)2cymene(1,2-,1,3-and1,4-(o-,m-andp-)isomers)l,3,5-(CH3)3C6H3mesitylenefulvene4.
5.
8RadicalsandionsRadicalsandionsarenotformedbyasubstitutionoperation,butbysubtractionoradditionofhydrogenatoms,hydronsorhydrides.
Theirnamesareformedusingsuffixesandprefixes,someofwhicharelistedinTable4.
14.
Table4.
14Somesuffixesusedtonameradicalsandions.
OperationSuffixRadicalsAnionsLossofifLossof2HLossofH-yl-ylideneordiyl*-ideCationsLossofH-AdditionofH-ylium-ium*Thesuffix'ylidene'isusedtorepresentradicalssuchasR-CHand/orR-CH,andthesuffix'diyl'whentheelectronsarelocalisedondifferentatoms.
95CHAPTER4Examples1.
CH3'methyl2.
CH2:and/orH2methylideneorcarbene3.
CH2-CHethane-1,2-diyl4.
CH3-CHethanideorethylanion5.
CH5methanium6.
CH3methyliumormethylcationThesesuffixesarecumulative,meaningthatmorethanonecanbepresentinaname,forinstancetorepresentradicalions.
Radicalscomebeforeanions,whichinturncomebeforecations,intheorderofseniorityforcitationassuffixes(cf.
Table4.
12).
Examples7.
CH2methyliumyl8.
CH4methaniumyl9.
CH-CHethan-2-ium-1-yl10.
CH2-CH2ethan-2-id-1-ylThetermsradicalcationorradicalion(+)maybeaddedtothenameoftheparenthydridewhenthepositionsoffreevalenciesand/orchargesarenotknown,orwhenitisnotdesirabletospecifythem.
Example11.
(CH6)±ethaneradicalcationorethaneradicalion(+)4.
5.
9StereochemicaldescriptorsTheuseofstereochemicaldescriptorsinbothnamesandformulaeisdealtwithinChapter3,Section3.
8(p.
21).
4.
6FUNCTIONALCLASSNOMENCLATURESubstitutivenomenclatureisthenomenclatureofchoiceinorganicchemistry.
However,itcannotbeusedtonameallclassesofcompound.
Salts,esters,acylhalidesandanhydridescannotbenamedsubstitutivelywhenthecharacteristicgroupischosenastheprincipalgroup,andfunctionalclassnames(formerlycalledradicofunctionalnames)arethenused.
Functionalclassnomenclatureisabinarysystemwidelyusedininorganicchemistry(seeintroductiontoChapter4).
Whereassubstitutivenamesaregenerallywrittenasoneword,binarynamesarecomposedoftwowords.
Thenamesofsaltsofcarboxylicacidsarebinary,asinsodiumacetate.
Namesofestersandacylhalidesareconstructedinasimilarway:methylacetateforCH3-COOCH3,methylchloroacetateforC1CH2-COOCH3,acetylchlorideforCH3-COC1andbenzoylbromideforC6H5-COBr.
Prefixesforthesegroupsareusedinsubstitutivenameswhentheprincipalgroup(cf.
Table4.
12)isnotanesteroranacylhalide.
96NAMINGOFSUBSTANCESExamples1.
C1OC-[CH2]2-COOH4-chloro-4-oxobutanoicacid2.
C6H5-COO-[CH2]3-COOH4-(benzoyloxy)butanoicacidFunctionalmodifiersareusedinbinarynomenclaturetonameanhydrides,e.
g.
aceticanhydridefor(CH3-CO)2O,andderivativesofketonesandaldehydessuchasoximes,hydrazonesandsemicarbazones,e.
g.
acetoneoximefor(CH3)2C=NOH.
975Aspectsofthenomenclatureoforganometalliccompounds5.
1GENERALOrganometalliccompoundsaredefinedascompoundscontainingadirectlinkbetweenacarbonatomandametal.
Whatconstitutesametalfornomenclaturepurposesisreallyrathervague.
ThepracticeinnomenclatureistoconsideranyelementotherthanC,Handtheraregasestobemetalsifthisisuseful.
Thenamesofsuchcompoundsreflecttheirconstitutionandaredrawnbothfromorganicnomenclatureandfrominorganicnomenclatures.
Thenamesoforganometalliccompoundsdemonstratethatnomenclaturesmustbeunifiedandadaptabletoanysituation.
Letustaketheexampleofanorganometalliccompoundderivedfromtin,e.
g.
[Sn(C2H5)4].
Notethatthesquarebracketsimplyacoordinationcompound.
Usingcoordinationnomenclature,itsnameisbasedonthoseofthecentralatom,tin,andoftheligands,ethyl.
Theresultingname,tetraethyltin,isconstructedaccordingtotheprinciplesofinorganicnomenclature(inbeinganadditivename)andorganicnomenclature(inbeingderivedfromaparenthydride,ethane).
However,thereisanotherapproachtonamethiscompound.
Thehydrideoftin,SnH4,issimilartothatofcarbon,CH4(methane).
AnamesimilartomethanecanbecoinedforSnH4byattachingtheending'ane'tothestemcharacteristicoftin,namelystann-.
Stannanecanbeconsideredasaparenthydrideandthusserveasthebasisofsubstitutivenames.
Thenametetraethylstannaneisarrivedatasasubstitutivename.
Thusorganometalliccompoundscanbenamedbyanadditiveorasubstitutiveprocess.
Additivenomenclatureisapplicabletoallorganometalliccompounds,butsubstitutivenomenclatureisarbitrarilyrestrictedtonamesofderivativesofspecificmetals,theelementsofGroups14,15,16and17,andboron.
5.
2DERIVATIVESOFMAINGROUPELEMENTS5.
2.
1SelectionofparenthydridesandtheirnamesCarbonis,ofcourse,uniqueinthenumberofhydridesitforms,buttheelementsintheproximityofcarboninthePeriodicTablehaveasimilar,ifmorerestricted,propensitytoformhydrides.
Silicon,germanium,boronandphosphorusareobviousexamples.
Forhydridesoftheseelements,andespeciallyfortheirorganicderiva-tives,themethodsofsubstitutivenomenclaturecanbeappliedtoobtainsuitablenames.
Itisgenerallyanarbitrarymattertodecidewheretoapplysubstitutivenomen-clatureinthesecases.
Table5.
1showstheelementstowhichbothCNICandCNOCapprovetheapplication.
Table5.
2givesthenamesofthecorrespondingmononu-clearparenthydrides.
Theonlyadditionalelementstowhichsubstitutivenomencla-turemaysometimesbeappliedarethehalogens,particularlyiodine.
98NOMENCLATUREOFORGANOMETALLICCOMPOUNDSTable5.
1Parenthydrideelements.
Group13Group14Group15Group16Group170FGroup18NeBCNAlSiPSClArGaGeAsSeBrKrInSnSbTeIXeTlPbBiPoAtRnSeveralpointsarisefromTables5.
1and5.
2.
Theending-anesignifiesthattheelementexhibitsitsstandardbondingnumber(i.
e.
theconventionalnumberofelectron-pairbonds),namely3forsimpleboronhydrides,4fortheGroup14elements,3forGroup15elementsand2forGroup16elements.
Whereotherbondingnumbersareexhibited,thisisindicatedusingtheX-convention(seetheGuidetoIUPACNomenclatureofOrganicCompounds,p.
21andtheNomenclatureofInorganicChemistry,p.
84).
Thealternativenamesappendedarecoordinationnames.
Examples1.
PH3,phosphaneortrihydridophosphorus2.
PH5,5-phosphaneorpentahydridophosphorus3.
SH,sulfaneordihydridosulfur4.
SHE,X6-sulfaneorhexahydridosulfurSeveralofthenamesfortheparenthydrides,althoughsystematic,arenotingeneraluse,andalternativesareapproved:theseareazane(ammoniaissanctionedbywideusage),oxidane(water)andsulfane(hydrogensulfide).
Thenamesofpolynuclearhydrides(i.
e.
compoundswithmoleculesconsistingofchains)areobtainedbyprefixingthe-anenamesofTable5.
2withtheappropriatemultiplicativeprefixesofdi-,tn-,tetra-,etc.
Table5.
2Mononuclearparenthydrides.
BH3boraneNH3azane*OH2oxidane*,tSiH4silanePH3phosphane*SH2sulfane*GeH4germaneAsH3arsane*SeH2selanetSnH4stannaneSbH3stibane*TeH2tellanetPbH4plumbaneBiH3bismuthanetPoH2polane*Phosphine,arsineandstibinemayberetainedfortheunsubstitutedmononuclearhydridesandforuseasderivedligandsandinformingcertainderivedgroups,buttheyarenotrecommendedfornamingsubstitutedderivatives.
Thesystematicnamesinsubstitutivenomenclatureforammonia(NH3)andwater(H20)areazaneandoxidane,respectively.
Thesenamesareusuallynotused,butareavailableifrequired.
Sulfane,whenunsubstituted,isusuallynamedhydrogensulfide.
ThenormalformulaeH20,H2S,H2Se,H2TeandH2Pohavebeenreversedforpurposesofcomparison.
tNamesbasedonsuchotherformsasoxane,germanane,selenane,telluraneandbismanecannotbeusedbecausetheyareusedasnamesforsaturatedsix-memberedheteromonocyclicringsbasedontheHantzsch—Widmansystem.
99CHAPTER5ExamplesSubstitutivenamesCoordinationnames5.
H2PPH2diphosphanetetrahydridodiphosphorus(P—P)6.
H3SnSnH3distannanehexahydridoditin(Sn—Sn)7.
SiH3SiH2SiH2SiH3tetrasilanedecahydridotetrasilicon(35i—Si)Thenamesofunsaturatedcompoundsarederivedbyusingappropriatesubstitu-tivenomenclaturerules.
Notethattrivialnamesarealsoallowedforparticularpolynuclearspecies,forexample,N2H4,diazane,commonlyknownashydrazine.
Foradiscussionofnamesofhydridesinwhichelementsexhibitnon-standardbondingnumbers,seetheNomenclatureofInorganicChemistry,p.
85.
NotethatforthehydridesofTable5.
1andtheirderivatives,substitutivenamesaregenerallypreferred.
5.
2.
2NamesofsubstitutedderivativesThepreferrednamesarealsoobtainedbyapplyingtheprinciplesofsubstitutivenomenclature.
Substituents,consideredasreplacinghydrogenatoms,arenamedusingprefixesoftheappropriategroupnamesandarecited,ifthereismorethanone,inalphabeticalorderbeforethenameoftheparenthydride,usingparenthesesandmultiplicativeprefixesasnecessary.
Examples1.
PH2(CH2CH)ethyiphosphane2.
Sb(CH=CH2)3trivinylstibane3.
Si(OCH2CH2CH3)C13trichloro(propoxy)silane4.
(C2H5)3PbPb(C2H5)3hexaethyldiplumbane5.
C3H7SnH2SnC12SnH2Brl-bromo-2,2-dichloro-3-propyl-tristannane6.
GeH(SCH3)3tris(methylsulfanyl)germaneWhereitisnotobviouswhichatomshouldbeselectedcentralatom,thechoicemaybemadeasindicatedintheNomenclatureofInorganicChemistry,p.
87:P,As,Sb,Bi,Si,Ge,Sn,Pb,B,5,Se,Te,C.
Examples7.
HCPHSiHmethyl(silyl)phosphane8.
Ge(C6H5)Cl2(SiC13)trichloro[dichloro(phenyl)germyl]silaneCoordinationnamescanbeproposedforallthesespecies,forexamplehexa-ethyldiplumbanemayalsobenamedhexaethyldilead(Pb—Pb)orbis(trimethyl-lead)(Pb—Pb).
Thereseemsnoobviousadvantageinthecoordinationnames,andthesubstitutivenamesareusuallyused.
Theseexamplesalsodemonstratehowthe-anenameoftheparenthydrideisadaptedtogivethenameofthecorrespondingsubstituentgroup,asthenamemethanegivesrisetothenamemethanyl,generallycontractedtomethyl.
Inthesecases,silanegivesrisetosilyl,germanetogermyl,etc.
,butphosphanetophosphanyl.
Theproblemisquitecomplexbecause,forexample,disilylmeans(SiH3)2whereas100NOMENCLATUREOFORGANOMETALLICCOMPOUNDSdisilanylmeansSiH3SiH2-.
ThereaderisreferredtotheNomenclatureofInorganicChemistry,Chapter7,formoredetaileddiscussion.
Finally,itshouldbenotedthatcertainelements,suchassulfurandnitrogen,havewell-developedalternativesystemsofnomenclaturebaseduponotherorganicnomenclatureprinciples.
ThereaderisreferredtotheNomenclatureofOrganicChemistryfordetails.
5.
2.
3SkeletalreplacementInsomecases,itmaybepreferabletoconsideraparenthydrideinwhichaskeletalcarbonatom(oratoms)ofahydrocarbonhas(have)beenreplacedbysomeotheratom(s).
Thefollowingexampledemonstratestheprinciple,evenifitistoosimpletotypifygeneralpractice.
Thus,Si(CH2CH3)2H2isprobablybestnameddiethylsilane.
However,ifwrittenintheformCH3-CH2-SiH2-CH2-CH3,itcanbeseentobeaderivativeofpentaneinwhichthecentralcarbonatomhasbeenreplacedbyasiliconatom.
Usingskeletalreplacementmethodology,thiscanalsobenamed3-sila-pentane,althoughthisisprobablynotasusefulasthesilanename.
Ingeneral,suchnamesshouldbeusedonlywhenfourormoreheteroatomsarepresent.
Themodifiedelementname'sila'indicatesreplacementinthecarbonskeleton,andsimilartreatmentcanbeappliedtootherelementnames.
TheparenthydridenamesofTable5.
2mayallbeadaptedinthiswayandusedinthesamefashionasintheoxa-azanomenclatureoforganicchemistry.
Ininorganicchemistry,amajoruseisinnamesofcyclicderivativesthathaveheteroelementatomsreplacingcarbonatomsinstructures.
ItmaybepossibletonamesuchspeciesbyHantzsch—Widmanprocedures(seep.
77),andtheseshouldalwaysbeusedwhenapplicable.
ThereaderisreferredtotheNomenclatureofInorganicChemistryandtotheNomenclatureofOrganicChemistryfordetailedtreatments.
Theapplicationcanbecomplex,butonoccasiontheusagecanbeadvantageous.
Examples1.
IBSCH32-(methylsulfanyl)-l,3,2-oxathiaborepineCH32.
l-methyldecahydro-l-aluminanaphthalene3.
6-methyl-1-borabicyclo[4.
2.
O]octane4.
_____I2,1,3-benzothiazastannoleSnH101CHAPTER55.
3ORGANOMETALLICDERIVATIVESOFTRANSITIONELEMENTSForthesederivatives,coordinationnomenclatureisgenerallypreferred.
Theproce-duresanddeviceshavebeendealtwithinChapter4,Section4.
4(p.
51),andthereaderisreferredthereandtotheNomenclatureofInorganicChemistryformoredetails.
1026Macromolecular(polymer)nomenclature6.
1DEFINITIONSThisdiscussionisbasedonthe1991editionoftheCompendiumofMacromolecularNomenclatureandseveralmorerecentrecommendationsoftheIUPACCommissiononMacromolecularNomenclature.
'.
Amacromolecule,orpolymermolecule,isamoleculeofhighrelativemolecularmass,thestructureofwhichessentiallycomprisesthemultiplerepetitionsofunitsderivedfrommoleculesoflowrelativemass.
.
Amonomerisasubstancecomposedofmonomermoleculesthatcanundergopolymerisation,therebycontributingconstitutionalunitstotheessentialstructureofamacromolecule.
Aconstitutionalunitisanatomorgroupofatoms(withpendantatomsorgroups,ifany)comprisingapartoftheessentialstructureofamacromol-ecule.
Polymerisationistheprocessofconvertingamonomer,oramixtureofmono-mers,intoapolymer.
Amonomericunitisthelargestconstitutionalunitcontributedbyasinglemonomermoleculetothestructureofamacromolecule.
Aconstitutionalrepeatingunitisthesmallestconstitutionalunit,therepetitionofwhichconstitutesaregularmacromolecule.
Aregularpolymerisasubstancecomposedofregularmacromolecules,thestructureofwhichessentiallycomprisestherepetitionofasingleconstitutionalunitwithallunitsconnectedidenticallywithrespecttodirectionalsense.
Anirregularpolymerisasubstancecomposedofirregularmacromolecules,thestructureofwhichessentiallycomprisestherepetitionofmorethanonetypeofconstitutionalunit,orofmacromolecules,thestructureofwhichcomprisesconsti-tutionalunitsnotallconnectedidenticallywithrespecttodirectionalsense.
Asingle-strandpolymeriscomposedofsingle-strandmacromolecules,thestruc-tureofwhichcomprisesconstitutionalunitsconnectedinsuchawaythatadjacentconstitutionalunitsarejoinedtoeachotherthroughtwoatoms,oneoneachconstitutionalunit.
Adouble-strandpolymeriscomposedofdouble-strandmacromolecules,thestructureofwhichcomprisesconstitutionalunitsconnectedinsuchawaythatadjacentconstitutionalunitsarejoinedtoeachotherthroughthreeorfouratoms,twoononesideandeitheroneortwoontheothersideofeachconstitutionalunit.
1.
IUPAC,CommissiononMacromolecularNomenclature,CompendiumofMacromolecularNomen-clature.
BlackwellScientificPublications,Oxford(1991).
IUPAC,CommissiononMacromolecularNomenclature,Nomenclatureofregulardouble-strand(ladderandspiro)organicpolymers.
PureAppl.
Chem.
,65,1561—1580(1993).
IUPAC,CommissiononMacromolecularNomenclature,Structure-basednomenclatureforirregularsingle-strandpolymers.
PureAppl.
Chem.
,66,873—879(1994).
IUPAC,CommissiononMacromolecularNomenclature,Graphicrepresentations(chemicalformulae)ofmacromolecules.
PureApp!
.
Chem.
,66,2469—2482(1994).
IUPAC,CommissiononMacromolecularNomenclature,Glossaryofbasictermsinpolymerscience.
PureApp!
.
Chem.
,68,2287—2311(1996).
103CHAPTER6Examplesofadouble-strandpolymerarealadderpolymerinwhichmacromoleculesconsistofanuninterruptedsequenceofringswithadjacentringshavingtwoormoreatomsincommon,andaspiropolymerinwhichmacromoleculesconsistofanuninterruptedsequenceofrings,withadjacentringshavingonlyoneatomincommon.
Ahomopolymerisapolymerderivedfromonespeciesofmonomer.
Acopolymerisapolymerderivedfrommorethanonespeciesofmonomer.
Ablockcopolymeriscomposedofblockmacromoleculesinwhichadjacentlinearblocksareconstitutionallydifferent,i.
e.
adjacentblockscompriseconstitutionalunitsderivedfromdifferentspeciesofmonomersorfromthesamespeciesofmonomerbutwithdifferentcompositionorsequencedistributionofconstitutionalunits.
Agraftcopolymeriscomposedofgraftmacromoleculeswithoneormorespeciesofblockconnectedtothemainchainasside-chains,theseside-chainshavingconstitutionalorconfigurationalfeaturesthatdifferfromthoseinthemainchain.
Anend-groupisaconstitutionalunitthatisanextremityofamacromolecule.
6.
2GENERALCONSIDERATIONSPolymersareunlikelow-molecular-weightcompoundsinthattheyhavenouniformstructureandareamixtureofmacromoleculesofdifferentlengthanddifferentstructuralarrangements,evenwhenderivedfromasinglemonomer.
Forinstance,poly(vinylchloride),derivedfromthepolymerisationofvinylchloride(chloroethene),CH2=CHC1,containsrepeatingunits-CH2-CHC1-.
How-ever,long-chainmoleculesareofvariouslengthsandtheunitsarenotnecessarilyalluniquelyorientedandjoinedinaregularfashion,whichwouldresultinthepolymerformulated:4CH2-CHCl.
Inadditionto'head-to-tail'links,-CH2-CHC1-CH2-CHC1-,otherlinkssuchas'head-to-head'or'tail-to-tail'canoccur,asin-CH2-CHC1-CHC1-CH2-CH2-CHC1-.
Thisbecomesevenmorecomplicatedinthestructureofacopolymerderivedfrommorethanonespeciesofmonomer,suchasstyreneandmethylacrylate,bothofwhichcontributeconstitutionalunits.
Examples-CH-CH2-I-CH-CH2-1.
s—2.
C=OO—CH3Thesecancombineinturninapolymericchaininavarietyofways,resultingintypessuchasunspecified,statistical,random,alternating,periodic,blockandgraftcopolymers.
Becausetheexactstructureofthepolymerisnotalwaysknown,twosystemsofmacromolecularnomenclaturehavebeendeveloped:source-basednomenclatureandstructure-basednomenclature.
104MACROMOLECULARNOMENCLATURE6.
3SOURCE-BASEDNOMENCLATUREThenameofthepolymerisformedbyattachingtheprefix'poly'tothenameoftherealorassumedmonomer,orthestartingmaterial(source)fromwhichthepolymerisderived.
Examples1.
polyacrylonitrile2.
polyethylene3.
poly(methylmethacrylate)4.
polystyrene5.
poly(vinylacetate)6.
poly(vinylchloride)Parenthesesareusedwhenthenameofthemonomerconsistsoftwoormorewords.
Forcopolymers,aconnective(infix)isinserted,whichdependsonwhatisknownaboutthearrangementoftheconstitutionalunits.
Examples7.
poly[styrene-co-(methylmethacrylate)]orcopoly(styrene/methylmethacrylate)(anunknownorunspecifiedarrangement)8.
poly(styrene-stat-acrylonitrile-stat-butadiene)orstat-copoly(styrene/-acrylonitrile/butadiene)(astatisticalarrangement,obeyingknownstatisticallaws)9.
poly[ethylene-ran-(vinylacetate)]orran-copoly(ethylene/vinylacetate)(arandomarrangement,withaBernoulliandistribution)10.
poly[(ethyleneglycol)-alt-(terephthalicacid)]oralt-copoly(ethyleneglycol/-terephthalicacid)(analternatingsequence)11.
glycol)-alt-(terephthalicacid)]-co-[(ethyleneglycol)-alt-(isophthalicacid)]]oralt-copoly[ethyleneglycol/(terephthalicacid;isophthalicacid)](anunspecifiedarrangementoftwoalternatingpairsofmonomers)12.
polystyrene-block-polybutadieneorblock-copoly(styrene/butadiene)(alineararrangementofblocks,suchas-AAAA-BBBB-)13.
polybutadiene-graft-polystyreneorgraft-copoly(butadiene/styrene)(agraftarrangement,suchas-AAA'AAA-BB16.
4STRUCTURE-BASEDNOMENCLATURE6.
4.
1Regularsingle-strandorganicpolymersForregularorganicpolymersthathaveonlyonespeciesofconstitutionalrepeatingunit(CRU)inasinglesequentialarrangementandconsistofsinglestrands,thenameisoftheformpoly(CRU).
105CHAPTER6TheCRUisnamedasanorganicdivalentgroupaccordingtotheusualrulesfororganicchemistry.
Thestepsinvolvedare:identificationoftheunit;orientationoftheunit;andnamingoftheunit.
Forinstance,inapolymersuchas-O-CH-CH2-O-CH-CH2-O-CH-CH2-O-ClClCltheCRUmaybeidentifiedinatleastthreeways:-O-CH-CH2--O-CH2-CH--CH2-O-CH-IorIorIClClClToobtainauniquename,asinglepreferredCRUmustbeselected.
Therefore,ruleshavebeendevelopedthatspecifybothseniorityamongsubunits,thatis,thepointatwhichtobeginwritingtheCRU,andalsothedirectioninwhichtomovealongthechaintoreachtheendoftheCRU.
Theorderofseniorityamongthetypesofdivalentgroupis:1heterocyclicrings;2chainscontainingheteroatoms;3carbocyclicrings;4chainscontainingonlycarbon.
Withineachstructuraltype,theseniorityisdictatedbytheseniorityofindividualconstituents.
Examplesofsomeoftherulesaregivenbelow:Forheterocyclicrings,aringsystemcontainingnitrogenisseniortoaringsystemcontainingaheteroatomotherthannitrogen,withfurtherdescendingorderofsenioritygovernedbythegreatestnumberofringsinaringsystem,thelargestTable6.
1SeniorityofringsystemsTheseniorityofringsystemsisdecidedbyapplyingthefollowingcriteria,successivelyintheordergiven,untilasingleringisleftunderconsideration.
(a)Allheterocyclesareseniortoallcarbocycles.
(b)Forheterocycles,theorderofseniorityis:1anitrogen-containingring;2aringcontaininganotherdifferentheteroatomashighaspossibleinTable4.
8;3asystemcontainingthegreatestnumberofrings;4asystemcontainingthelargestpossibleindividualring;5asystemcontainingthegreatestnumberofheteroatomsofanykind;6asystemcontainingthegreatestvarietyofheteroatoms;7asystemcontainingthegreatestnumberofheteroatomslistedearliestinTable4.
8;8afusedsystemwiththelowestlocantsfortheheteroatombeforefusion.
(c)Largestnumberofrings.
(d)Largestindividualringatfirstpointofdifference.
(e)Largestnumberofatomsincommonamongrings.
(f)Lowestletters(lowestmeansalowerthanb,etc.
)intheexpressionofringjunctionsinfusionnomenclature.
(g)Lowestnumbersatthefirstpointofdifferenceintheexpressionforringjunctions.
(h)Loweststateofhydrogenation.
(i)Lowestlocantforindicatedhydrogen.
(j)Lowestlocantforpointsofattachment(ifasubstituent).
(k)Lowestlocantforanattachedgroupexpressedasasuffix.
(1)Lowestlocantforsubstituentsnamedasprefixes.
(m)Lowestlocantforthatsubstituentnamedasprefixthatiscitedfirstinthename.
106MACROMOLECULARNOMENCLATUREindividualringinaringsystem,thelargestnumberofheteroatomsandthegreatestvarietyofheteroatoms(fordetails,seeTable6.
1).
Foranacyclicchaincontainingaheteroatom,oxygenisseniortosulfur,sulfurtonitrogen,nitrogentophosphorus,phosphorustosilicon,silicontogermanium,etc.
Forcarbocyclicrings,athree-ringsystemisseniortoatwo-ringsystem,atwo-ringsystemcontainingtwosix-memberedringsisseniortoonecontainingafive-andasix-memberedring,afusedtwo-ringsystem(twoatomscommontobothrings)isseniortoaspiroringsystem(oneatomincommon)ofthesamesizeandanunsaturatedringisseniortoasaturatedringofthesamesize.
Forchainscontainingcarbon,seniorityisdeterminedfirstbylength,thenbythenumberofsubstituents,thenbythelocantsand,finally,bythealphabeticalorderofsubstituents.
IftheCRUhasidenticalsubunitsseparatedbyothersubunits,thedirectionofcitationisdeterminedbytheshorterpathbetweenthem.
ThepreferredCRUistheonebeginningwiththesubunitofhighestseniority.
Toestablishdirection,oneproceedsfromthissubunittotheneighbouringsubunitofthesameornextinseniority.
Intheaboveexample,thesubunitofhighestseniorityisanoxygenatomandthesubunitnextinseniorityisasubstituted-CH2CH2-.
Thesubstitutedsubunitisorientedinsuchawaythatthesubstituent,thechlorineatom,isassignedthelowestlocant.
TheCRUiswrittentoreadfromlefttoright.
Thus,thepreferredCRUis-O-CH-CH2-Clandthepolymer*O-CH--CH2i—,isnamedpoly[oxy(1-chloroethylene)].
ThesecondexampleshowstheCRUstartingwithasubstitutednitrogenatomandproceedingthroughtheshortestpathtotheunsubstitutednitrogenatomandthenthroughacarbocycle.
—EN-CH2-NH—_-)—poly[(methylimino)methyleneimino-l,3-phenylene]ThethirdexampleshowstheCRUstartingwithaheterocyclicringandproceed-ingthroughasubstitutedcarbonatomtoaheteroatom.
C-0-CH4—Npoly(pyridine-3,5-diylcarbonyloxymethylene)107CHAPTER6ExamplesofsomecommonpolymersStructure-basednameSource-basedortrivialname*CHCH21.
poly(l-phenylethylene)polystyrene2.
*CH2poly(l-cyanoethylene)polyacrylonitrile__o-____-poly(oxy-l,4-phenylene)poly(phenyleneoxide)4.
-(0-CH-CH2-0-c},poly(ethyleneterephthalate)*NH—C—[CH2]4-C—NH-[CH2]6hpoly(iminoadipoyl-poly(hexamethyleneoiminohexamethylene)adipamide)CH-CHCH-CH2)-poly[(2,5-dioxotetrahydro-poly(maleicanhydride-alt-6.
furan-3,4-diyl)(l-styrene)0phenylethylene)]Iftheend-groupsofthechainareknown,theymaybespecifiedbyprefixestothenameofthepolymer,withthesymboladesignatingthebeginningorleft-handend-groupandthesymbol0)designatingtheotherend-group.
Example—a-(trichloromethyl)-co-7.
C13C/CH2Clchloropoly(l,4-phenylenemethylene)6.
4.
2Regulardouble-strandorganicpolymersInadouble-strandpolymer,themacromoleculesconsistofanuninterruptedse-quenceofringswithadjacentringshavingoneatomincommon(aspiropolymer)ortwoormoreatomsincommon(aladderpolymer).
Asforasingle-strandpolymer,asinglepreferredCRUmustbeselectedinordertoobtainauniquename.
TheCRUisusuallyatetravalentgroupdenotingattach-menttofouratomsandisnamedaccordingtotheusualrulesoforganicnomencla-ture.
Thenameofthepolymerisintheform:poly(CRU).
Becausethepolymerhasasequenceofrings,inordertoidentifyapreferred108MACROMOLECULARNOMENCLATURECRU,theringsmustbebrokenbyobservingthefollowingcriteriaindecreasingorderofpriority:1minimisethenumberoffreevalenciesintheCRU;2maximisethenumberofmost-preferredheteroatomsintheringsystem;3retainthemostpreferredringsystem;4choosethelongestchainforacyclicCRU.
Furtherdecisionsarebasedontheseniorityofringsystems(fordetails,seeTable6.
1),ontheorientationoftheCRUtogivethelowestfreevalencelocantatthelowerleftofthestructuraldiagramandonplacingtheacyclicsubunits,ifany,ontherightsideoftheringsystemwithintheCRU.
Forapolymerconsistingofadjacentsix-memberedsaturatedcarbonringsthenamebasedonthepreferredCRUispoly(butane-1,4:3,2-tetrayl)Forapolymerconsistingofalternatingsix-memberedsulfur-containingandketo-group-containingringspoly(1,4-dithiin-2,3:5,6-tetrayl-5,6-dicarbonyl)Forabenzobisimidazobenzophenanthroline-type(BBL)ladderpolymerderivedfrom1,4,5,8-naphthalenetetracarboxylicacidand1,2,4,5-benzenetetramine109thenamebasedonthepreferredCRUisCHAPTER6thenameispoly[(7-oxo-7H,1OH-benz[de]imidazo[4',5':5,6]benzimidazo-[2,1-a]isoquinoline-3,4:10,11-tetrayl)-10-carbonyl].
Forapolymerconsistingofadjacentcyclohexaneand1,3-dioxaneringsinaregularspirosequence,suchas:::(Dc>oo(Dc>ocIthenamebasedonthepreferredCRUis/O-CH2CH2-OCH2-CH\I/45\/ii1O\/tC36C'1\21/\78/\\o-CH2CH2-OCH2-CHnpoly(2,4,8,10-tetraoxaspiro[5.
5]undecane-3,3:9,9-tetrayl-9,9-diethylene)6.
4.
3Regularsingle-strandinorganicandcoordinationpolymersThenamesofinorganicandcoordinationpolymersarebasedonthesamefunda-mentalprinciplesthatweredevelopedfororganicpolymers.
Asinthenomenclatureoforganicpolymers,theserulesapplytostructuralrepresentationsthatmayattimesbeidealisedanddonottakeintoaccountirregularities,chainimperfectionsorrandombranching.
ACRUisselectedandnamed.
ThenameofthepolymeristhenameoftheCRUprefixedbytheterms'poly','catena'orotherstructuralindicator.
InordertoarriveatthepreferredCRU,thesenioritiesoftheconstituentsubunitsareconsidered,aswellasthepreferreddirectionforthesequentialcitation.
Theconstituentsubunitofhighestsenioritymustcontainoneormorecentralatoms;bridginggroupsbetweencentralatomsinthebackboneofthepolymercannotbeseniorsubunits.
Thisisconsistentwiththeprincipleofcoordinationnomencla-ture,inwhichtheemphasisislaidonthecoordinationcentre.
ExamplesCH31.
±Sn-)catena-poly[dimethyltin]CH3110nMACROMOLECULARNOMENCLATUREFCH32.
—(--i—ii-)—catena-poly[(difluorosilicon)(dimethylsilicon)]FCH3Theaboveexamplescontainhomoatomicbackbones.
However,coordinationpolymerscommonlyconsistofasinglecentralatomwithabridgingligand.
Suchapolymerisnamedbycitingthecentralatomprefixedbyitsassociatednon-bridgingligands,followedbythenameofthebridgingligandprefixedbytheGreeklettert.
ExamplesNH33.
*Cl*catena-poly[(amminechlorozinc)-.
t-chloro]HCH341T-*catena-poly[(dihydroboron)-t-(dimethy1amido)]HCH3Multiplebridgingligandsbetweenthepairofcentralatomsarecitedinalphabet-icalorder.
ItalicisedelementsymbolsindicatingthecoordinatingatomsinbridgingligandsarecitedintheorderofdirectionoftheCRUandareseparatedbyacolon.
Example/EtEt(,,S—catena-poly[copper-[.
t-chloro-bis-j.
t-(diethylCu—Cl—Cu—Cltdisulfide-S:S')]-copper-j.
t-chloro]\\EtEtn6.
4.
4Regularquasi-single-strandcoordinationpolymersAregularlinearpolymerthatcanbedescribedbyapreferredCRUinwhichonlyoneterminalconstituentsubunitisconnectedthroughasingleatomtotheotheridenticalCRUisaquasi-single-strandpolymer.
Suchpolymersarenamedsimilarlytosingle-strandcoordinationpolymers.
Examplespdcatena-poly[palladium-di-p-chloro],-ci1111CHAPTER62.
catena-poly[silicon-di-pi-thio]3.
ptcatena-poly[platinum(i-bromo-j.
t-chloro)]4.
catena-poly[titanium-tri--chloro]6.
4.
5Irregularsingle-strandorganicpolymersIrregularpolymersarenamedbyplacingtheprefix'poly'beforethestructure-basednamesoftheconstitutionalunits,collectivelyenclosedinparenthesesorbrackets,withtheindividualconstitutionalunitsseparatedbyobliquestrokes.
Forinstance,apartiallyhydrolysedpoly(vinylacetate)containingunits—CH-CH2-—CH—CH2-O-C-CH3andOH0isnamedpoly(l-acetoxyethylene/l-hydroxyethylene).
Acopolymerofvinylchlorideandstyreneconsistingofunitsjoinedhead-to-tail—CH—CH2-—CH-CH2-Clandisnamedpoly(l-chloroethylene/l-phenylethylene).
AchlorinatedpolyethyleneconsistingofunitsCl—CH-,—C-,—CH-ClClisnamedpoly(chloromethylene/dichloromethylene/methylene).
Adiblockcopolymerinwhichtheblocksofpoly(ethyleneoxide)andpoly(vinylchloride)arejoinedbyaspecificjunctionunitCH3*CH2-CH2-O,—Si—,CH-CH2CH3Clisnamedpoly(ethyleneoxy)—dimethylsilanediyl—poly(1-chloroethylene).
112MACROMOLECULARNOMENCLATURE6.
5TRADENAMESANDABBREVIATIONSTradenamesandabbreviationsarefrequentlyusedintheliteratureandinoralcommunication,e.
g.
'nylon66'forpoly(hexamethyleneadipamide),'Teflon'orPTFEforpoly(tetrafluoroethylene)and'Lucite'orPMMAforpoly(methylmeth-acrylate).
Othercommonabbreviationsarelistedbelow:ABSacrylonitrile/butadiene/styrenecopolymerPANpolyacrylonitrilePBTpoly(butyleneterephthalate)PEOpoly(ethyleneoxide)PETpoly(ethyleneterephthalate)PPpolypropylenePSpolystyrenePVACpoly(vinylacetate)PVALpoly(vinylalcohol)PVCpoly(vinylchloride)PVDFpoly(vinylidenedifluoride)1137Biochemicalnomenclature7.
1INTRODUCTIONSystematicsubstitutivenomenclaturemaybeusedtonameallorganicmolecules.
However,thosethatareofanimalorvegetableoriginhaveoftenreceivedtrivialnames,suchascholesterol,oxytocinandglucose.
Biochemicalnomenclatureisbaseduponsuchtrivialnames,whichareeithersubstitutivelymodifiedinaccordancewiththeprinciples,rulesandconventionsdescribedinChapter4,Section4.
5(p.
70),ortransformedandsimplifiedintonamesofstereoparenthydrides,i.
e.
parenthydridesofaspecificstereochemistry.
Thesenamesarethenmodifiedbytherulesofsubstitutivenomenclature.
Threeclassesofcompoundwillbediscussedheretoillustratethebasicapproach:carbohydrates;aminoacidsandpeptides;andlipids.
Fordetails,see:BiochemicalNomenclatureandRelatedDocuments,2ndEdition,PortlandPress,London(1992).
7.
2CARBOHYDRATENOMENCLATUREOriginally,carbohydratesweredefinedascompoundssuchasaldosesandketoseshavingthestoichiometricformulaC(H2O),hence'hydratesofcarbon'.
Thegenericterm'carbohydrates'includesmonosaccharides,oligosaccharidesandpolysaccha-rides,aswellassubstancesderivedfrommonosaccharidesbyreductionofthecarbonylgroup(alditols),byoxidationofoneormoreterminalgroupstocarboxylicacid(s)orbyreplacementofoneormorehydroxylgroup(s)byahydrogenatom,anaminogroup,thiolgrouporsimilargroup.
Italsoincludesderivativesofthesecompounds.
Thetermcarbohydrateissynonymouswiththetermsaccharide.
Trivialnamesarecommonincarbohydratenomenclature.
Fifteenofthemformthebasisofthesystematicnomenclature.
Theyareassignedtothesimplealdoses(polyhydroxyaldehydes),fromtriosetohexoses.
Triose:glyceraldehyde(notglycerose)Tetroses:erythrose,threosePentoses:arabinose,lyxose,ribose,xyloseHexoses:allose,altrose,galactose,glucose,gulose,idose,mannose,taloseAmongtheketo-hexoses,fructoseisofmajornaturaloccurrence.
Astereodescriptor,DorL,isusedtoindicatetheabsoluteconfigurationoftheentiremolecule.
Referenceismadetotheconfigurationofglyceraldehydethroughareferencecarbonatom,whichisthecarbonatomreceivingthehighestnumericallocant(marked—intheexamplesbelow),thelowestpossiblelocantbeinggiventothecarbonatombearingtheprincipalcharacteristicgroup,whichisacarbonylgroupinaldosesandketoses.
114BIOCHEMICALNOMENCLATUREExamplesCHOCH2OHCHOHOHC=OCHOH—4---OHHOHHOHCHOHOOHCH2OHCH2OHCH2OHCH2OHCH2OH1.
D-glyceraldehyde2.
D-threose3.
D-ribOSe4.
D-g1UCOSe5.
D-fructOSeNamesofcyclised(hemi-acetalised)aldosesandketosescontaintheinfixespyranorfurantoindicatethesix-orfive-memberedheterocyclicstructureandastereo-descriptor,aor,toindicatetheconfigurationoftheanomericorhemi-acetalcarbonatom.
ExamplesHOIjHII1HIII1CH2OHCH2OHCH2OH6.
a-D-glucopyranose7.
a-D-ribofuranose8.
-D-fructofuranoseAlthoughthenamesofthesaccharidesaregenerallytrivial,systematicnomencla-tureisusedtonametheirderivatives.
Becausetrivialnamesarenotamenabletothetreatmentsusuallyappliedtothenamesofordinaryparenthydrides,manyadapta-tionsarenecessaryandsomepeculiaritiesmustbenoted.
Forexample,substitutioncanbemadeonanoxygenatominthecaseofestersandethers.
Itischaracterisedbythesymbol0,whichisplacedafterthelocant.
Thecompoundprefixdeoxy-iscomposedoftheprefixesde-,meaning'without'insubtractivenomenclature,andoxy-,toindicatethesubtractionofanoxygroupfroman-OHgroup:C-O-H—kC-H.
Suchanoperationisneededwhenan-OHgroupisreplacedbyanothergroup,suchasanaminogroup.
115CHAPTER7ExamplesCHOf-OHf-OHf-Hf-OHAcidandalcoholderivativesarenamedbychangingtheending-oseofthesaccharidenameintotheappropriateendingtosignifyafunctionalchange,forinstance,-onicor-aricacid,and-itol.
ExamplesxHIOH13.
X=CHO14.
X=COOH15.
X=COOH16.
X=CH2OHY=CH2OHY=CH2OHY=COOHY=CH2OHD-glucoseD-gluconicacidD-glucaricacidD-glucitolThegenerictermglycosidesdefinesallmixedacetalsformedbytheacetalisationofthecyclicformsofaldosesandketoses.
Glycosylgroupsaremonosaccharidesthathavelosttheiranomeric-OHgroup;thesuffix-ylisusedtoindicatethechangethathasoccurredatC-i.
17.
methyla-D-glucofuranosideHHOHHOHHOHJHO—'CH2OH18.
a-D-glucopyranosyl19.
a-D-mannopyranosylbromideCHOHOAcHOHHOAcHOHCH2OH9HOHHOHHOHHOMeCH2OHH—H—HO—H—HOHHNH2HOHHOHHO—'CH2OHCH31011129.
2,4-di-O-acetyl-D-glucose(Ac=-OC-CH3)10.
4-O-methyl-a-D-glucopyranose(Me=-CH3)11.
6-deoxy-D-gulose12.
2-amino-2-deoxy-a-D-glucopyranoseHOHHOHHOHYExamplesH—HO—HO—H—H—BrHHOHCH2OH116BIOCHEMICALNOMENCLATUREDisaccharidesarenamedbyaddingthenameofaglycosylgroupasaprefixtothatofthemonosaccharidechosenasparent,asexemplifiedbya-lactose(aHaworthperspectiveformulaandaconformationalformulaareshown).
CH2OHThreeformsofabbreviatednomenclature(extended,condensedandshort)maybeused;D-glucopyranoseisrepresentedasD-GlcpintheextendedformandGlcinthecondensedform.
Thelinkingatomsaredesignatedbylocants,andtheaorconfigurationoftheanomericcarbonatomsisalsoindicated.
Thesugarraffinosebecomes(extendedform)orGal(al-6)Glc(al-2f)Fruf(condensed)orGala-6Glca-fFruf(short).
Aldosesaresystematicallynamedaspentoses,hexoses,heptoses,octoses,nonoses,etc.
,accordingtothetotalnumberofcarbonatomsinthechain.
Theconfigurationisdescribedbyappropriatestereodescriptors(glycero-fromglyceralde-hyde,gluco-fromglucose,galacto-fromgalactose,etc.
)togetherwiththeappropriateDorL,andtheseareassembledaccordingtospecificrulesinfrontofthebasicname.
Namesofketosesarecharacterisedbytheending-ulose.
Examples20.
D-glycero-D-gluco-heptose(I=D-gluco,11=D-glycero)21.
L-glycero-D-galacto-heptaricacid(I=D-galacto,11=L-glycero)22.
L-gluco-hept-2-ulose(I=L-glUCO)117HCH2OHHOH-D-galactopyranosyl-(l---'4)-a-D-glucopyranoseH—HO—H—H—H—CHOOHHHHOHHOH—OHIICOOHHOHHOHHOHHOH—IHOHIIICH2OHC=OHOHHOHHOHHOHCH2OH20COOH21CH2OH22CHAPTER77.
3NOMENCLATUREANDSYMBOLISMFORAMINOACIDSANDPEPTIDESApeptideisanycompoundproducedbyamideformationbetweenacarboxylgroupofoneaminoacidandanaminogroupofanother.
Theamidebondsinpeptidesarecalledpeptidebonds.
Thewordpeptideisusuallyappliedtocompoundswhoseamidebonds(sometimescalledeupeptidebonds)areformedbetweenC-iofoneaminoacidandN-2ofanother,butitincludescompoundswithresidueslinkedbyotheramidebonds(sometimescalledisopeptidebonds).
PeptideswithfewerthanaboutiO—20residuesmayalsobecalledoligopeptides;thosewithmoreresiduesarecalledpolypeptides.
Polypeptidesofspecificsequenceofmorethanabout50residuesareusuallyknownasproteins,butauthorsdiffergreatlyonwheretheystarttoapplythisterm.
Aminoacidsarerepresentedintwoways:eitherasH2N-CHR-COOHorasthezwitterionicformH3N-CHR-COO.
Althoughthesecondoftheseformsisover-whelminglypredominantinthecrystalandinsolution,itisgenerallymoreconve-nienttonamethemandtheirderivativesfromthefirstform.
Theyarenormalorganiccompoundsandaretreatedassuchasfarasnumberingandnamingareconcerned,althoughtrivialnamesareretainedforallnaturalaminoacids.
Examplesi.
H2N-CH2-COOCH3methylglycinate,glycinemethylester2.
CH3-CH(NH2)-CONH2alaninamide,alanineamide3.
HOCH2-CH(NHCOCH3)-COOHN-acetylserineTherearetwogenerallyacceptedsystemsofabbreviationfortrivialnames,usingeitheroneorthreeletters.
Thechoiceofformtouseisgenerallydeterminedbycircumstances.
Normally,three-lettersymbolsareused,andone-lettersymbolsarereservedforlongsequencesofaminoacids.
AlistofsuchsymbolsisshowninTable7.
1.
ThestereodescriptorsDandLareusedwithreferencetotheDconfigurationofglyceraldehyde.
Table7.
1Namesandtheirabbreviationsandsymbolsforaminoacids.
*TrivialnameSymbolsTrivialnameSymbolsAlanineAlaALeucineLeuLArginineArgRLysineLysKAsparagineAsnNMethionineMetMAsparticacidAspDPhenylalaninePheFCysteineCysCProlineProPGlutamineGlnQSerineSerSGlutamicacidGluEThreonineThrTGlycineGlyGTryptophanTrpWHistidineHisHTyrosineTyrYIsoleucineIleIValineValV*ThegeneralrepresentationforanunspecifiedaminoacidisXaa,symbolX.
118BIOCHEMICALNOMENCLATURECOO-COO-CHOH3NH÷H3N-C-HH--C—RHOH1RRCOO-CH2OHLLLDThree-lettersymbolsandstandardgroupabbreviationsareusedtodesignateaminoacidsfunctionalisedon-COOHorsubstitutedon-NH2.
Modificationsareindicatedbyhyphensinabbreviations.
Examples4.
N-acetylglycineAc-Gly5.
glycineethylesterGly-OEt6.
N2-acetyllysineAc-Lys7.
O'-ethylN-acetylglutamateAc-Glu-OEtSubstitutiononotherpartsoftheaminoacidisexpressedbyadifferentsymbolism.
ExamplesEt8.
S-ethylcysteineorCys(Et)CysNO29.
3-nitrotyrosine3TyrThepeptideH2N-CH2-CO-NH-CH(CH3)-COOHisnamedglycylalanineandsymbolisedasGly-Ala.
Theaminoacidwiththefree-COOHgroupischosenastheparent.
Thenameoftheotheraminoacid,modifiedbythesuffix-yl,becomesaprefixtoit.
Thesymbolismappliedtoapeptideisverypreciseandelaborate.
Thesymbol-Alastandsfor-NH-CH(CH3)-COOH,andthecorrespondingnameisthatoftheaminoacid.
ThesymbolGly-meansH2N-CH2-CO-andcorrespondstoanameendingin-yl.
InthepeptideGly-Gly-Ala,Gly-signifiesH2N-CH2-CO-and-Gly--HN-CH2-CO-,bothofthesegroupsbeingnamedglycyl,givingthenameglycyl-glycylalanine.
AhyphenindicatesaC-l-to-N-2peptidebond.
Glutamicacidcanbeboundthrougheitherorbothofitstwocarboxylgroups,andGreeklettersaoryareusedtoindicatethepositionofthelink.
Example10.
HOOC-CH2-CH2-CH(NH2)-CO-a-glutamyl54321ThedipeptideN-a-glutamylglycineisabbreviatedasGlu-Gly.
N-y-Glutamyl-glycineisrepresentedbythebondsymbol119CHAPTER7LorPLExamplesGluGlyIi11.
I,[orI[orGlu(-Gly)LGlyGluGluGlyGlutathioneis12.
GluorrlLorGlu(-Cys-Gly)Cys-GlyGluCys-GlyGreatcareshouldbeexercisedinpresentingtheseformulae,becauseasimplelinebetweenGluandCyswouldcorrespondtoathiolesterbetweentheycarboxylofGluandtheSHgroupofCys.
ExampleGlu13.
ICys-GlyCyclicpeptidesinwhichtheringconsistssolelyofaminoacidresidueswitheupeptidelinksmaybecalledhomodeticcyclicpeptides.
Threerepresentationsarepossible.
GramicidinSisgivenasanexample.
Inthisdecapeptide,allaminoacidsareL,withtheexceptionofPhewhichisD,asisshownbyD-PheorDPhe.
Examples14.
cyclo(-Val-Orn-Leu-D-Phe-Pro-Val-Orn-Leu-D-Phe-Pro-)15.
16.
Val—Orn—Leu-*DPhe---PrPro—o-Phe—Leu—Orn--ValHeterodeticcyclicpeptidesarepeptidesconsistingonlyofaminoacidresidues,butthelinksformingtheringarenotsolelyeupeptidebonds;oneormoreisanisopeptide,disulfide,ester,etc.
Examples17.
Oxytocinys-Tyr-Ile-Gln-Asn-èys-Pro-Leu-Gly-NH218.
Cyclicesterofthreonylglycylglycylglycine+hr-Gly-Gly-Gly_]120BIOCHEMICALNOMENCLATURE7.
4LIPIDNOMENCLATURELipidsaresubstancesofbiologicaloriginthataresolubleinnon-polarsolvents.
Therearesaponifiablelipids,suchasacylglycerols(fatsandoils),waxesandphospholipids,aswellasnon-saponifiablecompounds,principallysteroids.
Theterm'fattyacid'designatesanyofthealiphaticcarboxylicacidsthatcanbeliberatedbyhydrolysisfromnaturallyoccurringfatsandoils.
'Higherfattyacids'arethosethatcontaintenormorecarbonatoms.
Neutralfatsaremono-,di-ortn-estersofglycerolwithfattyacids,andarethereforetermedmonoacyiglycerol,diacylgly-cerolandtriacylglycerol.
Trivialnamesareretainedforfattyacidsandtheiracylgroups:stearicacid,stearoyl;oleicacid,oleoyl.
Estersfromglycerolareusuallynamedbyaddingthenameoftheacylgrouptothatofglycerol.
ExamplesCH2OHCH2OHCH2-0—CO-[CH2]16-CH3HNH21.
CHOH2.
CH—O—CO—[CH2]16-CH33.
HOHCH2OHCH2—0—CO—[CH2]16-CH3CH2-[CH2]13—CH3glyceroltristearoylglycerolsphinganineCompoundssimilartoglycerol,calledsphingoids,arederivativesofsphinganine(D-erythro-2-aminooctadecane-i,3-diol).
Thetrivialnamesphinganineimpliesthestereochemistry;theuseofthestereodescriptorD-erythrointhesystematicnameistobenoted.
Phospholipidsarelipidscontainingphosphoricacidasamono-ordi-ester.
WhenglycerolisesterifiedonC-ibyamoleculeofphosphoricacid,theresultisachiralglycerolphosphate.
Aspecificnumberingisnecessarytonameitwithoutambiguity.
Thesymbolsn(forstereospecificallynumbered)isused:thus,D-glycerolandL-glycerolphosphatesareeasilyrecognised,thesn-glyceroli-phosphatebeingtheenantiomerofsn-glycerol3-phosphate.
ExamplesCH2OHCH2—O-P03H2HOCH5.
HO-C-'HCH2-O-P03H2CH2OHsn-glycerol3-phosphatesn-glyceroli-phosphateAcompletenameisgivenforaphospholipidasshownbelow.
Notethatthename'ethanolamine'isanallowednamefor2-aminoethanol.
CH2-O-CO-[CH2]14-CH36.
CH3-[CH2]16-CO-O-CHCH2-0-PO(OH)-0-CH2-CH2-NH2i-palmitoyl-2-stearoyl-sn-glycero-3-phosphoethanolamine121CHAPTER77.
5STEROIDNOMENCLATURESteroidsarecompoundspossessingthetetracyclicskeletonofcyclopenta[a]phenan-threne(1)oraskeletonderivedtherefrombyoneormorebondscissionsorringexpansionsorcontractions.
Naturalsteroidshavetrivialnames.
Thenomenclatureofsteroidsisnotbasedonthesetrivialnames,butonafewstereoparenthydridesthatarecommontomanycompounds.
Substitutivenomenclatureisusedtodesig-natecharacteristicgroupsandunsaturation.
Structuralmodificationsareexpressedbyappropriatenon-detachableprefixes.
3IIJ"iiiii:c9:15:2423(1)H(2)Someofthestereoparenthydridesareshownbelow.
Theyrepresenttheabsoluteconfigurationsandarenumberedasshownin(2).
Accordingtotheprojectionformula,substituentsaredesignateda(belowtheplaneoftheskeleton)and1(abovethatplane).
Whennoindicationisgiven,theconfigurationsatcarbonatoms8,9,10,13,14,17and20areasshownin(2).
TheconfigurationatC-Siseither5aor51;itmustalwaysbestatedinthename.
Anyunknownconfigurationisdenotedby(Greekxi).
Instructuralformulaebroken,thickandwavybonds(rr')denotethestereodescriptorsa,and,respectively.
ExamplesR'n1(a)R=H;R'=CH3estrane(b)R=R'=CH3androstane4.
cholestane122RH2.
pregnane3.
cholaneExamplesoftrivialandsystematicnamesH0-estradiol5.
estra-l,3,5(l0)-triene-3,l713-diolBIOCHEMICALNOMENCLATURE7.
HO'cholicacid3a,7a,12a-trihydroxy-53-cho1an-24-oicacidNon-detachableprefixesareusedtoindicatemodificationsaffectingrings:homo-(enlarging),seco-(opening)andnor-(contracting).
Locantsaresuppliedasnecessarytoindicatethepositionsofmodification.
Examples9.
4a-homo-7-nor-5a-androstane10.
22,3-seco-5a-androstane123Htestosterone6.
173-hydroxyandrost-4-en-3-one8.
HHOHcholesterolcholest-5-en-3-olHH8NomenclatureinthemakingNomenclatureisnotastaticsubject.
Itchangesasnewkindsofcompoundaresynthesisedandnewproceduresanddeviceshavetobeinvented.
Fullerenesareacaseinpoint,andtheirdetailednomenclatureandnumberingarecurrently(1997)underdiscussion.
Evenestablishedproceduresarecontinuouslybeingreviewedandrevised,buttheprinciplesestablishedinthissurveyarelikelytoremainrecom-mendedfortheforeseeablefuture.
Asahelpinthisdirection,theCNOChasrecentlypublishedAGuidetoIUPACNomenclatureofOrganicChemistry,Recommendations1993.
Itincludesrevisions,publishedandhithertounpublished,tothe1979EditionofNomenclatureofOrganicChemistry.
Thevariationsofoxidationstateandstereochemistryimposeduponinorganiccompoundsbythepresenceoftransitionmetalsandnon-stoichiometry,etc.
makeinorganicnomenclaturemuchmoredifficulttounify.
Organicnomencla-tureiscurrentlybetterintegratedthaninorganicnomenclature.
Onerecentdevelopmentinsubstitutivenomenclaturethatwehaveemployedinthispresentationistoplacelocantsimmediatelybeforethepartofthename(suffix,infix,prefixordescriptor)thattheyqualify.
TheCNOCGuidealsorecommendsthatthetraditionalnamesofalkylgroupsbesupplementedbyalkanylnamesthatarederivedbyaddingthesuffix-yltothenameoftheparenthydride,ratherthanreplacingtheending-anebythesuffix-yl,asincurrentpractice.
Forexample,threenameswillnowcompetefor(CH3)2CH-:isopropyl,1-methylethylandpropan-2-yl.
Thelastsystematicnameisshort,easytounderstandandtouseandfullyabletocopewithfurthersubstitution.
Thesubstitutedgroup(C1CH2)2CH-canbenamed2-chloro-l-(chloromethyl)ethylor,inthenewform,1,3-dichloropropan-2-yl.
Thislastnameisshorterandquiteappealing.
Thegeneraltrendinsubstitutivenomenclatureistousefewertrivialorretainednamesandtoapproachsubstitutivenomenclaturemoresystematically.
Atotalof209trivialnamesaretoberetained:81forparenthydridesand58(thoseinChapter4,Section4.
5.
7,p.
91)forfunctionalparenthydrides.
Thesearesowellanchoredinnomenclaturethattheywillprobablysurviveforagreatmanyyears.
Finally,70trivialnames,suchasisobutaneandneopentane,arestillallowedtobespecificfornon-substitutedcompounds.
PresumablysomeofthesewillbediscardedduringlaterrevisionsoftheNomenclatureofOrganicChemistry.
ThenomenclatureoforganometalliccompoundsiscurrentlybeingreviewedjointlybytheCNICandtheCNOC.
Somesystematicbutnotwidelyusednamesaretoberecommendedfromnowon.
Namessuckasphosphineandarsinehavebeensupersededbyphosphaneandarsane.
Thenamesazaneanddiazanehavebeensuggestedtoreplaceammoniaandhydrazine.
Thisisunlikelytohappeninthenearfuture,althoughazocompounds(R-N=N-R)arenamedbyusingdiazeneasaparenthydride.
Forinstance,dimethyldiazeneisthesubstanceformerlyknownasazomethane.
Sulfane,H2S,isusedtonamesulfides,e.
g.
diethylsulfane,(C2H5)2S,whichisalsoknownasdiethylsulfide.
Theprefixmercapto-isreplacedbythesystematicnamesulfanyl,leadingtonamessuchassulfanylaceticacidforHS-CH2-COOH.
124NOMENCLATUREINTHEMAKINGTheCommissionontheNomenclatureofInorganicChemistryiscurrentlyproducingafurthervolumeoftheNomenclatureofInorganicChemistry,whichwilldealwithmorespecialisedaspectsofinorganicnomenclaturenotcurrentlytreatedinthe1990version.
Forexample,onechapterwillbedevotedtothenomenclatureofnitrogenhydrides,anothertothenomenclatureofiso-andheteropolyanionsandyetanothertotechniquesandrecommendationsforabbreviationsofnames,especiallyligandnames.
Thesechaptersareinnovativebutalsocodifyagreatdealofestab-lishedpractice.
Anareaofcurrentdevelopmentisthenomenclatureoforganometalliccom-pounds.
OrganometalliccompoundsofMainGroupelementscan,toafirstapprox-imation,beconsideredtobederivativesofhydrides,andthemethodsofsubstitutivenomenclaturecanbeapplied.
Eventhen,theaccessibilityofdifferentoxidationstates,aswithphosphorus(ni)andphosphorus(v),introducescomplications.
Transi-tionmetalorganometalliccompoundsareevenmoredifficulttotreat,andthedevelopmentofaunified,self-consistentandacceptedandappliednomenclatureisnoteasy.
Witnessthedifferentways(ic,ianditalicisedsymbols)fordenotingdonoratomsinligands.
Inotherareas,suchasoxoacids,agreatdealoftraditional,inadequatesemi-systematicnomenclature(forexample,thenamesofphosphorusacids)willhavetobeabandonedbeforeamorerigorousnomenclaturecanbeadoptedandgenerallyunderstood.
Thereismuchworkyettodo.
TheCommissiononMacromolecularNomenclatureiscurrentlyworkingontheextensionofmacromolecularnomenclaturetobranchedandcyclicmacromolecules,micronetworksandpolymernetworks,andtoassembliesheldtogetherbynon-covalentbondsorforces,suchaspolymerblends,interpenetratingnetworksandpolymercomplexes.
ThegreatdreamofthefoundersofsystematicorganicnomenclatureattheGenevaConferencein1892wastheprovisionofauniquenameforagivencompound.
Thisisnowbecomingfeasible,atleastinsubstitutivenomenclature.
Auniquenameismorethanevernecessaryinlegaldocumentsandpatents.
Astradeandcommercebecomeevenmoreinternationalandasgeneralinterests,suchastheenvironment,healthandsafety,becomemorewidespread,theuniquenamebe-comesanecessity.
Nomenclaturistsmustreducechoice,andsystemsandrulesshouldsuffernoexceptions.
Theemergenceofcomputerisednomenclaturewillhelptofulfilthatgoal.
125IndexPagereferencestotablesappearinboldtype.
'a'prefixes,Hantzsch—Widmansystem78abbreviationsaminoacids118,119carbohydrates117ligands56,57—9,125peptides119—20polymers113aceticacid91acidhydrogen12,48,69acidsnomenclature27biochemicalnomenclature116fatty121formulae12functionalclassnomenclature27,96—7seealsocarboxylicacids,oxoacids,sulfonicacidsacycliccompounds82—3,83,88,92,106acylhalides,functionalclassnomenclature96acylhydrides,prefixes85additioncompounds15,28,45seealsocoordinationcompoundsadditivenomenclatureseecoordination-typenomenclatureaggregations7,67alchemy1alcohols15amino,ligands57anions47—8biochemicalnomenclature116functionalclassnomenclature27suffixesandprefixes84,85aldehydes85,93,97aldoses114,117aliphaticgroups14,71alkalimetals7alkanesalkylgroups72—3,124branched71—3cyclic76—80,83—7parenthydrides91—3principalchainselection74—5substitutive-typenomenclature70—5unbranched70—3unsaturated81—3allotropes7alphabeticalorderbinary-typenomenclature28,29,30—43,48coordination-typenomenclature55,56,66groups13,86inindexes9,12macromolecularnomenclature106—7,111substitutive-typenomenclature74,76,83,86,100amides,suffixesandprefixes85,93aminesparenthydrides92,95suffixesandprefixes89aminoacids118—20aminoalcohols,ligands57ammonialigands56,59ammonium46anhydrides,functionalclassnomenclature97anions7,125binary-typenomenclature30—43,47—8citationsequence12,96coordination-typenomenclature26,56,59,69—70organometalliccompounds55substitutive-typenomenclature47seealsoionsannulenes76,77—8arbitrarynomenclature26,85,87,98aromaticgroups14arrows52—3,66,114—15assembliesrings83—4ringswithchains84atomicmassesseemassnumberatomicnumber3,4-6,7,22atomsnames1,3,4—5PeriodicTable3,6classes7,12symbols1,3,4—6,7,13citationsequence9,11—13modifiers3,5,11seealsoelementsazaneseeammonialigandsazocompounds124azote,nitrogencompounds5benzene17,76,84,87,92Berthollet1Berzelius1binary-typenomenclature26,27—49additioncompounds28,45alphabeticalordering28,29,30—43,48anions30—43,47—8cations30—43,45charge30—43,44—8citationsequence12,13,44,48electronegativity27—9enclosingmarks29groups30—43hydrates45,48inorganiccompounds26,27—49ions30—43ligands30—43oxidationstates28,44—5salts45,48seealsofunctionalclassnomenclaturebiochemicalnomenclature1,2,92aminoacids118—20carbohydrates114—17lipids121peptides118—20steroids122—3blockcopolymers104bondsmetal—ligand51—70,99,100structuralformulae10—11,16—25,122—3braces11,51,60—2seealsoenclosingmarksbracketsseeparentheses,squarebracketsbranchedchains71—3,82—3,88—9,125bridgedcompounds53—4,66—8,78—80,110—11127INDEX128Cahn—Ingold—Prelog(CIP)rules22,24carbocycles75,77—80,83,106—7,106carbohydrates114—17carbonylcompounds,parenthydrides91,93carboxylicacidsfunctionalclassnomenclature96parenthydrides92,94—5suffixesandprefixes84,87catena-110—ilcations7binary-typenomenclature30—43,45citationsequence12,96coordination-typenomenclature56,59seealsoionscentralatoms13—15,26,51—2,55—6,66,69,98,100,110chainsbranched71—3,82—3,88—9,125citationsequence15,106—10organometalliccompounds99—100polymers103—ilprincipal74—5,82—3,83,85,88—9,90andringassemblies83—4,88—9seniority83unbranched11,70—3,85chargenumberatoms3,5binary-typenomenclature30—43,44—8coordination-typenomenclature55—6,59,66,69—70molecularformulae7,10suffixes1chelates52,56,57—8ChemicalAbstractsCollectiveIndexnames62chirality23—5cis—transisomers22,65citationsequencebinary-typenomenclature12,13,44,48chainspecies15coordinationcompounds13—14,66electronegativity12elements9,11—13formulae9,11—16groups13—14intermetalliccompounds13ions12,48,96polymers106—ilradicals96salts48CommissiononMacromolecularNomenclature(COMN)seeCompendiumofMacromolecularNomenclatureCommissiononNomenclatureofInorganicChemistry(CNIC)seealsoNomenclatureofInorganicChemistrycoordination-typenomenclature26,65,66,67,68,69formulae12substitutive-typenomenclature98—101substitutive-typenomenclature27,98—101CommissiononNomenclatureofOrganicChemistry(CNOC)seeGuidetoIUPACNomenclatureofInorganicChemistryCompendiumofMacromolecularNomenclature1,2,103,125complexescoordination-typenomenclature51ions13—14polymeric125seealsocoordinationcompoundscompositionalformulaeseeempiricalformulaecompounds,definition7condensedformulaeiiconformationconformationalisomers23projections20,117constitutionalrepeatingunit(CRU)105—12coordinationcompoundscis—transisomers22,65enclosingmarksii,51,55,60—2mononuclear55—65,110—12polynuclear66—8structuralformulae16—17,65,67symbolcitationsequence13—14seealsocomplexes,ligandscoordination-typenomenclaturealphabeticalordering55,56,66chargenumber55—6,59,66,69—70hydrides46—8italicisation63,66—8kappa(K)convention63—4ligands26,51—9,60-2,63—70organometalliccompounds54—5,98,100,102oxidationstates55—6,59,69—70oxoacidsandrelatedanions26,69—70polymers110—12salts55—6siliconcompoundsSicopolymers104,105,112cycliccompoundscarbocyclic75,77—80,84,106—7,106heterocyclic57,75—6,77—80,84,86,90,101,106—10,106,115inorganic51ligands57macrocyclic58—9,77—8macromolecularnomenclature125monocyclic76,77—8,86peptides120polycyclic78—80,86polymers108—10principalringselection83—4,106ringassemblies83—4structuralformulae16,23,75—80seealsoringsandringsystemscyclohexane,structuralformula23definitions3—8macromoleculesandpolymers103—4denticity53,63—4descriptors2,22,65,67deuterium5,7diamines89diastereoisomers24diketones,ligands57discontinuities,suffixesandprefixes88donor—acceptorcomplexesseeadditioncompoundsdoublesalts48Dumas1electronegativitybinary-typenomenclature27—9symbolcitationsequence12,13electroneutrality10elementarysubstances3,7seealsoelementselementselecronegativity12names1,3,4—5PeriodicTable3,6classes7,12sequence12substituentgroups50symbols1,3,4—6,7,13citationsequence9,11—13modifiers3,5,11typical7seealsoatomsempiricalformulae9,27relativeproportions5,9enantiomers23—5enclosingmarksbinary-typenomenclature29,44—5coordination-typenomenclature11,51,55,60—2formulae11,13—14molecularions12oxidationstateand/orchargenumber44—8polycycliccompounds78—80,85seealsobraces,parentheses,squarebracketsend-groups,polymers108Englishnames3enols15—16estersbiochemicalnomenclature115functionalclassnomenclature96prefixes85eta(q)haptosymbol54—5ethanes,polyhalogenated86ethersbiochemicalnomenclature115functionalclassnomenclature27parenthydrides90,93prefixes85Ewens—BassettNumberseechargenumberfac-isomers65fattyacids121ferrocene54Fischerprojection17,19formulaeacids12condensed11coordinationcompounds55—6empirical9,27groups12—16isomers21—5,65molecular9—10structural10—11,16—21,65,67symbolcitationsequence9,11—16Fourcroy1fullerenes124functionalclassnomenclature27,49,96—7functionalgroups14,15—16,70monofunctional88parenthydrides84—93,124polyfunctional84—91fusedpolycyclicsystems78—80,106gases7—8GenevaConference(1892),organiccompounds1,71,125geometricdescriptors2,22,65Germanicnames,elements4—5glycosides116-17graftcopolymers104Greeknameselements4—5prefixes44groupsaliphatic14alkyl72—3,124alphabeticalordering13,86aromatic14binary-typenomenclature30—43centralatoms13—15citationsequence13—14formulae12—16functional1—2,14,15—16,70,84—93polyatomic13prefixes88substituents48—9,50,73suffixes85GuidetoJUPACNomenclatureofOrganicCompounds1,2,124—5GuytondeMorveau1INDEXhalogencompounds7,98prefixes85Hantzsch—Widmansystem77—8,81,96,99,101'a'prefixes78hapticity54—5heterocycles,ligands57,75—6,77—80,84,86,90,101,106—10,106,115homopolymers104hydrates,binary-typenomenclature45,48hydrazine100,124hydridescoordinationnomenclature46—8nitrogenhydrides125organicderivatives46—7,89organometalliccompounds98,125substitutive-typenomenclature27,46—8,89seealsoparenthydrideshydrocarbonsacyclic82—3ligands57monocyclic86parenthydrides91,93polycyclic86polysubstituted86seealsoalkaneshydrogen7binary-typenomenclature28indicated76isotopes5,7seealsoacidhydrogenhydrogensulfide99,124hydrons46,47,48,69hydroxycompounds,parenthydrides91—2,94indexes,symbolcitationsequence9,11—13infinitepolymers,metals7infixesbiochemicalnomenclature1,115copolymers105inorganiccompounds1,2binary-typenomenclature26,27—49enclosingmarks11functionalclassnomenclature49oxidationstates124polyhedralsymbols18—19,20—1coordinationcompounds53,65polymers110—12ringsandchains51stereochemistry16—17,20—1,124substitutive-typenomenclature48inorganic—debornomenclature27intermetalliccompounds,symbolcitationsequence13InternationalUnionofBiochemistryandMolecularBiology(IUBMB)1,2129INDEX130InternationalUnionofPureandAppliedChemistry(IUPAC)1,2,3ioniccompounds7,10,12ions3,7binary-typenomenclature30—43molecular12,13—14polyatomic10,13,28,29,44structuralformulae10—11suffixesandprefixes95symbolcitationsequence12seealsoanions,cationsisomers21—5cis—trans22,65conformers23enantiomers23—5isotopes5,7italicisation63,66—8,80,110-12IUPACseeInternationalUnionofPureandAppliedChemistry(IUPAC)kappa(K)convention,coordination-typenomenclature63—4ketonesfunctionalclassnomenclature96ligands57parenthydrides93pseudo93suffixesandprefixes84,85,89—90laboratoryshorthandnames26ladderpolymers109lambda(X)convention,organometalliccompounds99Latinnamesanions29,30—43elements4—5latticecompoundsseeadditioncompoundsLavoisier1Liebig1ligands1abbreviations56,57—9,125anionic56,59binary-typenomenclature30—43bridging53—4,66—8,110—12cationic56,59chelating52,56chirality24citationsequence13—14,16coordination-typenomenclature26,51—9,60-2,63—70donoratoms63—4,125neutral56,59structuralformulae16—17,65,67substitutive-typenomenclature48—9trivialnames57—9seealsocoordinationcompoundslipids121liquids7—8locants1biochemicalnomenclature114—15,117,123functionalgroups84-91macromolecularnomenclature109substitutive-typenomenclature71—2,73—4,76—8,81—3,83,106,124macrocycles77—8ligands58—9macromolecularnomenclature51,92,103—12,125alphabeticalordering106—7,111italicisation111macromoleculesseepolymersmaingroupelements7mancudes75,76,77—9,81,89,91massnumber5,7mer-isomers65mesocompounds24—5metalsinfinitepolymers7symbolcitationsequence66seealsointermetalliccompounds,organometalliccompoundsmixtures7,104modifiersatomicsymbols3,5coordination-typenomenclature63—4structuralformulae11molarmasses9molecularbiology1,2molecularcompoundsformulae9—11,16—25substitutive-typenomenclature49,51molecularweight9molecules7formulae9—11,16—25ions12,13—14isomers21—5monocycles76,77—8mu(pS)designator66—8,111multiplicativeprefixesbinary-typenomenclature28,29,44,45coordination-typenomenclature56,59,66—8substitutive-typenomenclature71,73,79—83,88—91,99—100multipliers,additioncompounds15namestems78naphthalene89—90neutronnumber5Newmanprojection19—20nitriles,suffixesandprefixes85,93nitrocompounds,prefixes85nitrogencompoundsazote5hydrides125parenthydrides92nitrosocompounds,prefixes85NomenclatureofInorganicChemistry1,2,124—5non-stoichiometriccompounds10,51,124non-systematicnamesseetrivialnamesnuclearity54nuclides5numericalprefixesseemultiplicativeprefixesobliquestrokes112organiccompounds1,2acids27classes14,85enclosingmarks11functionalclassnomenclature27,96functionalgroups14,15—16,70,84—93polyhedralsymbols16,18—19stereochemistry22—5,96,114—23structuralformulae11,16,21—5substitutive-typenomenclature1,27,48—9,50,70—95seealsopolymersorganic—deoxynomenclature27organometalliccompounds1,124—5coordination-typenomenclature54—5,98,100,101lambda(X)convention99oxidationstates55,125INDEX77,78,81,96,99,101131parenthydndes98—101,124,125substitutive-typenomenclature98—101,125transitionelements69,102,124,125oxidaneseewateroxidationstatesbinary-typenomenclature28,44—5coordination-typenomenclature55—6,59,69—70inorganiccompounds124organometalliccompounds55,125oxoacids125acidnomenclature27,51anionformation47—8binary-typenomenclature29,44coordination-typenomenclature26,69—70parenthydrides1,2biochemicalnomenclature114—23cyclic75—80,84functionalgroups91—3,124functionalised84-91mononuclear99,111organometalliccompounds98—101,124,125polynuclear99—100skeletalreplacement101substitutive-typenomenclature27,46—9,51,70—80,98—101trivialnames91—3,93—4,99—100,124unsaturatedcompounds81—3,87parentheses11,56,59,60—2,66—8,88,100polymers105,112seealsoenclosingmarkspeptides118—20PeriodicTable3,6,7perspectiveseeprojectionsphenols15suffixesandprefixes85phospholipids121polyatomicsubstances5,7groups13ions10,13,28,29,44polycycles78—80polyhalogenatedethanes86polyhedralsymbols16—17,18—19,20,22coordinationcompounds53,65,67polymers1,2,92abbreviations113assemblies125blends125block104citationsequence106—11complexes125coordination110—11copolymers104,105,112definitions103—4double-strand108—10end-groups108graft104homopolymers104inorganic110-11irregular112ladder109linear111networks125nomenclature51,102—11single-strand105—8,110-11spiro110structure103—12tradenames113poly(vinylchloride)104prefixes1—2'a'78acylhydrides85alcohols84,85aldehydes85amides85amines89ammine-56aqua-56biochemicalnomenclature115—17,123carboxylicacids84,85catena-110—11cyclichydrocarbons86—7cyclicparenthydrides76,77—8,83,106dehydro-81—3deoxy-115—16detachable74,85,87esters85ethers85functionalclassnomenclature96—7galacto-117gluco-117glycero-117halo-56halogencompounds85Hantzsch—Widmansystemhomo-123hydro-81—3hypo-69ions95,95ketones84,85mercapto-124—5meta-69nitriles85nitrocompounds85nitrosocompounds85non-detachable76—83,91,123nor-123organiccompoundgroups70,84—91organometalliccompounds100,124—5ortho-79—80phenols85phenyl-80poly-105—12polyhalogenatedethanes86radicals95seco-123sulfonicacids85seealsomultiplicativeprefixesprojections17—25,122—3conformation20,117Fischer17,19Newman19—20proteins118protonnumber5provisionalnames3,9punctuationmarks2racemates25radicalssubstitutive-typenomenclature48—9,50suffixesandprefixes95radicofunctionalnomenclatureseefunctionalclassnomenclaturerelativeproportions,empiricalformulae5,9replacementnomenclature27,70,77—9seealsosubstitutive-typenomenclatureringsandringsystemsseniority106seealsocycliccompoundsINDEX132romannumerals,oxidationstateand/orcharge44—8rotation,conformationalisomers23saccharidesseecarbohydratessaltsbinary-typenomenclature45,48coordination-typenomenclature55—6functionalclassnomenclature96—7Schiffbase,ligands58senioritychains83ringsystems106siliconcompounds51sodiumchloride7solids7—8source-basedmacromolecularnomenclature109spirocompounds78—80spiropolymers110squarebrackets11,78—80,98coordinationcompounds51,56,60—2seealsoenclosingmarksstatesofmatter7—8stereochemicaldescriptors2stereochemistrybiochemicalnomenclature114—23inorganiccompounds16—17,20—1,124organiccompounds22—5,96seealsostructuralformulaestereoisomers22—5steroids122—3stilbene87stoichiometrybinary-typenomenclature26,45carbohydrates114formulae10structuralformulae2,10—11descriptors67inorganiccompounds16—17,20—1isomers21—5,65organiccompounds11,16,17polyhedralsymbols16,18—19,20—1,65,67polymers103—12three-dimensional10,16—25,65seealsostereochemistrystructure-basedmacromolecularnomenclature105—12styrene87subscriptsseemodifierssubstitutive-typenomenclature1,27,50,125alkanes70—5alphabeticalordering74,76,83,86,100anions47biochemical114—23cycliccompounds75—80italicisation80ligands48—9molecularcompounds49,51organometalliccompounds98—101,125parenthydrides84—93radicals48—9,50ringassemblies83—4unsaturatedcompounds75,81—7,83,106seealsoprefixes,suffixessubtractivenomenclature27suffixes1—2-acene79—80-a!
88alcohols84aldehydes85,93-amide88,93amides85,93-amine89amines89-ane71—2,81,98,99—101,124-aricacid116-ate29,44,47—8,56-ato56-carbaldehyde88,93-carbonitrile88-carboxamide88-carboxylicacid88carboxylicacids84,85cycliccompounds85,89,106-diyl82-ene81—3-ic28,69,93-ide29,47,56-ido56-io49-ionic116ions95-ite47,56-ito56-ito!
116-ium46ketones84,85-nitrile88nitriles85,93-o56-oicacid88-olactam90-olactone90-one90-onitrile93-onium46organiccompoundgroups70,84—5,88—91organometalliccompounds124-ose114—17-ous28,69phenols85radicals95romannumerals44—5su!
fonicacids85-u!
ose117-y!
48—9,72—3,82,83—6,116,119,124-ylidene82,83—6-yne81—3sulfaneseehydrogensulfidesulfany!
compounds124—5sulfates14sulfonicacids,suffixesandprefixes85sulfurcompounds,thi5superscriptsseemodifiersthi,sulfurcompounds5thiocyanates15three-dimensionalstructuresinorganiccompounds16-17,20-1isomers21—5,65organiccompounds10—11,16polyhedra!
symbols16,18-19,20-1,65projections17—25,122—3toluene87tradenames,polymers113trans-isomers22,65transitionelements7,69,102,124,125tritium5,7trivialnames2,26a!
kanes71—3a!
kylgroups72—3,124amines89,96aminoacids118,119ammonium46benzenes84carbohydrates114—17carbonylcompounds93,114—17carboxylicacids94—5elements3classes7ethers93hydrides47hydrocarbons93hydroxycompounds94ions30—43,69—70ketones93ligands57—9lipids121organiccompounds1,94-5oxoacids69—70parenthydrides91—3,93—4,99—100,124peptides118polyatomicgroups29,30—43,44polycycles79polymers105,107steroids122—3substituentgroups49unsaturatedcompounds82,100unsubstitutedcompounds94,99INDEXuniquenames2,125unpairedelectrons3unsaturatedcompoundsprincipalchainselection81—3,83,85,89,91principalringselection83—5,106substitutive-typenomenclature75,81—7,83,100,106unsubstitutedcompounds92,94-5,99valency51,82,83—4,109vonBaeyerbridgedsystems78—80water7,8,99ligands56,59Wernercomplexes1,51133